Sorry, there was an unknown error. in store designer theme edit

[sivajik34]

When i click edit in store designer theme it will pop up with this message "When you edit a theme, we save it as a unique version in My Customizations."
if i click ok it will give following error.
Sorry, there was an unknown error.

exception.log
2014-11-24T17:59:28+00:00 DEBUG (7): Exception message: Unable to resolve the source file for 'frontend/Magento/blank/en_US/preview_image_546f220881720.jpeg'
Trace: #0 /var/www/html/magento2/app/code/Magento/Core/Model/Theme/Image/Path.php(104): Magento\Framework\View\Asset\File->getSourceFile()
#1 /var/www/html/magento2/lib/internal/Magento/Framework/View/Design/Theme/Image.php(226): Magento\Core\Model\Theme\Image\Path->getPreviewImagePath(Object(Magento\Core\Model\Theme))
#2 /var/www/html/magento2/lib/internal/Magento/Framework/View/Design/Theme/Image.php(165): Magento\Framework\View\Design\Theme\Image->getPreviewImagePath()
#3 /var/www/html/magento2/app/code/Magento/Core/Model/Theme/Domain/Physical.php(89): Magento\Framework\View\Design\Theme\Image->createPreviewImageCopy(Object(Magento\Core\Model\Theme))
#4 /var/www/html/magento2/app/code/Magento/DesignEditor/Controller/Adminhtml/System/Design/Editor/Launch.php(151): Magento\Core\Model\Theme\Domain\Physical->createVirtualTheme(Object(Magento\Core\Model\Theme))
#5 /var/www/html/magento2/var/generation/Magento/DesignEditor/Controller/Adminhtml/System/Design/Editor/Launch/Interceptor.php(114): Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch->execute()
#6 /var/www/html/magento2/lib/internal/Magento/Framework/App/Action/Action.php(118): Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch\Interceptor->execute()
#7 /var/www/html/magento2/app/code/Magento/Backend/App/AbstractAction.php(247): Magento\Framework\App\Action\Action->dispatch(Object(Magento\Framework\App\Request\Http))
#8 [internal function]: Magento\Backend\App\AbstractAction->dispatch(Object(Magento\Framework\App\Request\Http))
#9 /var/www/html/magento2/var/generation/Magento/DesignEditor/Controller/Adminhtml/System/Design/Editor/Launch/Interceptor.php(49): call_user_func_array(Array, Array)
#10 /var/www/html/magento2/lib/internal/Magento/Framework/Interception/Chain/Chain.php(83): Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch\Interceptor->___callParent('dispatch', Array)
#11 /var/www/html/magento2/lib/internal/Magento/Framework/Interception/Chain/Chain.php(76): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\DesignE...', 'dispatch', Object(Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch\Interceptor), Array, 'adminAuthentica...')
#12 /var/www/html/magento2/app/code/Magento/Backend/App/Action/Plugin/Authentication.php(113): Magento\Framework\Interception\Chain\Chain->Magento\Framework\Interception\Chain{closure}(Object(Magento\Framework\App\Request\Http))
#13 [internal function]: Magento\Backend\App\Action\Plugin\Authentication->aroundDispatch(Object(Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#14 /var/www/html/magento2/lib/internal/Magento/Framework/Interception/Chain/Chain.php(81): call_user_func_array(Array, Array)
#15 /var/www/html/magento2/lib/internal/Magento/Framework/Interception/Chain/Chain.php(76): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\DesignE...', 'dispatch', Object(Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch\Interceptor), Array, 'designLoader')
#16 /var/www/html/magento2/app/code/Magento/Core/App/Action/Plugin/Design.php(57): Magento\Framework\Interception\Chain\Chain->Magento\Framework\Interception\Chain{closure}(Object(Magento\Framework\App\Request\Http))
#17 [internal function]: Magento\Core\App\Action\Plugin\Design->aroundDispatch(Object(Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#18 /var/www/html/magento2/lib/internal/Magento/Framework/Interception/Chain/Chain.php(81): call_user_func_array(Array, Array)
#19 /var/www/html/magento2/var/generation/Magento/DesignEditor/Controller/Adminhtml/System/Design/Editor/Launch/Interceptor.php(89): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\DesignE...', 'dispatch', Object(Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch\Interceptor), Array, 'adminMassaction...')
#20 /var/www/html/magento2/app/code/Magento/Backend/App/Action/Plugin/MassactionKey.php(51): Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch\Interceptor->Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch{closure}(Object(Magento\Framework\App\Request\Http))
#21 [internal function]: Magento\Backend\App\Action\Plugin\MassactionKey->aroundDispatch(Object(Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#22 /var/www/html/magento2/var/generation/Magento/DesignEditor/Controller/Adminhtml/System/Design/Editor/Launch/Interceptor.php(94): call_user_func_array(Array, Array)
#23 /var/www/html/magento2/var/generation/Magento/DesignEditor/Controller/Adminhtml/System/Design/Editor/Launch/Interceptor.php(129): Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch\Interceptor->___call('dispatch', Array, Array)
#24 /var/www/html/magento2/lib/internal/Magento/Framework/App/FrontController.php(63): Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch\Interceptor->dispatch(Object(Magento\Framework\App\Request\Http))
#25 [internal function]: Magento\Framework\App\FrontController->dispatch(Object(Magento\Framework\App\Request\Http))
#26 /var/www/html/magento2/var/generation/Magento/Framework/App/FrontController/Interceptor.php(48): call_user_func_array(Array, Array)
#27 /var/www/html/magento2/lib/internal/Magento/Framework/Interception/Chain/Chain.php(83): Magento\Framework\App\FrontController\Interceptor->___callParent('dispatch', Array)
#28 /var/www/html/magento2/var/generation/Magento/Framework/App/FrontController/Interceptor.php(88): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\Framewo...', 'dispatch', Object(Magento\Framework\App\FrontController\Interceptor), Array, 'install')
#29 /var/www/html/magento2/lib/internal/Magento/Framework/Module/Plugin/DbStatusValidator.php(93): Magento\Framework\App\FrontController\Interceptor->Magento\Framework\App\FrontController{closure}(Object(Magento\Framework\App\Request\Http))
#30 [internal function]: Magento\Framework\Module\Plugin\DbStatusValidator->aroundDispatch(Object(Magento\Framework\App\FrontController\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#31 /var/www/html/magento2/var/generation/Magento/Framework/App/FrontController/Interceptor.php(93): call_user_func_array(Array, Array)
#32 /var/www/html/magento2/var/generation/Magento/Framework/App/FrontController/Interceptor.php(115): Magento\Framework\App\FrontController\Interceptor->___call('dispatch', Array, Array)
#33 /var/www/html/magento2/lib/internal/Magento/Framework/App/Http.php(133): Magento\Framework\App\FrontController\Interceptor->dispatch(Object(Magento\Framework\App\Request\Http))
#34 /var/www/html/magento2/lib/internal/Magento/Framework/App/Bootstrap.php(270): Magento\Framework\App\Http->launch()
#35 /var/www/html/magento2/index.php(42): Magento\Framework\App\Bootstrap->run(Object(Magento\Framework\App\Http))
#36 {main}

2014-11-24T17:59:28+00:00 ERR (3):
exception 'LogicException' with message 'Unable to resolve the source file for 'frontend/Magento/blank/en_US/preview_image_546f220881720.jpeg'' in /var/www/html/magento2/lib/internal/Magento/Framework/View/Asset/File.php:129
Stack trace:
#0 /var/www/html/magento2/app/code/Magento/Core/Model/Theme/Image/Path.php(104): Magento\Framework\View\Asset\File->getSourceFile()
#1 /var/www/html/magento2/lib/internal/Magento/Framework/View/Design/Theme/Image.php(226): Magento\Core\Model\Theme\Image\Path->getPreviewImagePath(Object(Magento\Core\Model\Theme))
#2 /var/www/html/magento2/lib/internal/Magento/Framework/View/Design/Theme/Image.php(165): Magento\Framework\View\Design\Theme\Image->getPreviewImagePath()
#3 /var/www/html/magento2/app/code/Magento/Core/Model/Theme/Domain/Physical.php(89): Magento\Framework\View\Design\Theme\Image->createPreviewImageCopy(Object(Magento\Core\Model\Theme))
#4 /var/www/html/magento2/app/code/Magento/DesignEditor/Controller/Adminhtml/System/Design/Editor/Launch.php(151): Magento\Core\Model\Theme\Domain\Physical->createVirtualTheme(Object(Magento\Core\Model\Theme))
#5 /var/www/html/magento2/var/generation/Magento/DesignEditor/Controller/Adminhtml/System/Design/Editor/Launch/Interceptor.php(114): Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch->execute()
#6 /var/www/html/magento2/lib/internal/Magento/Framework/App/Action/Action.php(118): Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch\Interceptor->execute()
#7 /var/www/html/magento2/app/code/Magento/Backend/App/AbstractAction.php(247): Magento\Framework\App\Action\Action->dispatch(Object(Magento\Framework\App\Request\Http))
#8 [internal function]: Magento\Backend\App\AbstractAction->dispatch(Object(Magento\Framework\App\Request\Http))
#9 /var/www/html/magento2/var/generation/Magento/DesignEditor/Controller/Adminhtml/System/Design/Editor/Launch/Interceptor.php(49): call_user_func_array(Array, Array)
#10 /var/www/html/magento2/lib/internal/Magento/Framework/Interception/Chain/Chain.php(83): Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch\Interceptor->___callParent('dispatch', Array)
#11 /var/www/html/magento2/lib/internal/Magento/Framework/Interception/Chain/Chain.php(76): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\DesignE...', 'dispatch', Object(Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch\Interceptor), Array, 'adminAuthentica...')
#12 /var/www/html/magento2/app/code/Magento/Backend/App/Action/Plugin/Authentication.php(113): Magento\Framework\Interception\Chain\Chain->Magento\Framework\Interception\Chain{closure}(Object(Magento\Framework\App\Request\Http))
#13 [internal function]: Magento\Backend\App\Action\Plugin\Authentication->aroundDispatch(Object(Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#14 /var/www/html/magento2/lib/internal/Magento/Framework/Interception/Chain/Chain.php(81): call_user_func_array(Array, Array)
#15 /var/www/html/magento2/lib/internal/Magento/Framework/Interception/Chain/Chain.php(76): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\DesignE...', 'dispatch', Object(Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch\Interceptor), Array, 'designLoader')
#16 /var/www/html/magento2/app/code/Magento/Core/App/Action/Plugin/Design.php(57): Magento\Framework\Interception\Chain\Chain->Magento\Framework\Interception\Chain{closure}(Object(Magento\Framework\App\Request\Http))
#17 [internal function]: Magento\Core\App\Action\Plugin\Design->aroundDispatch(Object(Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#18 /var/www/html/magento2/lib/internal/Magento/Framework/Interception/Chain/Chain.php(81): call_user_func_array(Array, Array)
#19 /var/www/html/magento2/var/generation/Magento/DesignEditor/Controller/Adminhtml/System/Design/Editor/Launch/Interceptor.php(89): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\DesignE...', 'dispatch', Object(Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch\Interceptor), Array, 'adminMassaction...')
#20 /var/www/html/magento2/app/code/Magento/Backend/App/Action/Plugin/MassactionKey.php(51): Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch\Interceptor->Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch{closure}(Object(Magento\Framework\App\Request\Http))
#21 [internal function]: Magento\Backend\App\Action\Plugin\MassactionKey->aroundDispatch(Object(Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#22 /var/www/html/magento2/var/generation/Magento/DesignEditor/Controller/Adminhtml/System/Design/Editor/Launch/Interceptor.php(94): call_user_func_array(Array, Array)
#23 /var/www/html/magento2/var/generation/Magento/DesignEditor/Controller/Adminhtml/System/Design/Editor/Launch/Interceptor.php(129): Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch\Interceptor->___call('dispatch', Array, Array)
#24 /var/www/html/magento2/lib/internal/Magento/Framework/App/FrontController.php(63): Magento\DesignEditor\Controller\Adminhtml\System\Design\Editor\Launch\Interceptor->dispatch(Object(Magento\Framework\App\Request\Http))
#25 [internal function]: Magento\Framework\App\FrontController->dispatch(Object(Magento\Framework\App\Request\Http))
#26 /var/www/html/magento2/var/generation/Magento/Framework/App/FrontController/Interceptor.php(48): call_user_func_array(Array, Array)
#27 /var/www/html/magento2/lib/internal/Magento/Framework/Interception/Chain/Chain.php(83): Magento\Framework\App\FrontController\Interceptor->___callParent('dispatch', Array)
#28 /var/www/html/magento2/var/generation/Magento/Framework/App/FrontController/Interceptor.php(88): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\Framewo...', 'dispatch', Object(Magento\Framework\App\FrontController\Interceptor), Array, 'install')
#29 /var/www/html/magento2/lib/internal/Magento/Framework/Module/Plugin/DbStatusValidator.php(93): Magento\Framework\App\FrontController\Interceptor->Magento\Framework\App\FrontController{closure}(Object(Magento\Framework\App\Request\Http))
#30 [internal function]: Magento\Framework\Module\Plugin\DbStatusValidator->aroundDispatch(Object(Magento\Framework\App\FrontController\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#31 /var/www/html/magento2/var/generation/Magento/Framework/App/FrontController/Interceptor.php(93): call_user_func_array(Array, Array)
#32 /var/www/html/magento2/var/generation/Magento/Framework/App/FrontController/Interceptor.php(115): Magento\Framework\App\FrontController\Interceptor->___call('dispatch', Array, Array)
#33 /var/www/html/magento2/lib/internal/Magento/Framework/App/Http.php(133): Magento\Framework\App\FrontController\Interceptor->dispatch(Object(Magento\Framework\App\Request\Http))
#34 /var/www/html/magento2/lib/internal/Magento/Framework/App/Bootstrap.php(270): Magento\Framework\App\Http->launch()
#35 /var/www/html/magento2/index.php(42): Magento\Framework\App\Bootstrap->run(Object(Magento\Framework\App\Http))
#36 {main}

system.log

2014-11-24T17:59:30+00:00 ERR (3): Cache file with merged layout: LAYOUT_adminhtml_STORE1_1a6aacbf92975cb72fbaa28e5d3264ea9: Please correct the XML data and try again.
2014-11-24T17:59:30+00:00 ERR (3): Cache file with merged layout: LAYOUT_adminhtml_STORE1_1cf9ab1b1723bedc1dcd665a812b00335: Please correct the XML data and try again.
2014-11-24T17:59:30+00:00 ERR (3): Cache file with merged layout: LAYOUT_adminhtml_STORE1_16f1b068ec7ccf4878f9284dd1137afd1: Please correct the XML data and try again.
2014-11-24T17:59:33+00:00 ERR (3): Cache file with merged layout: LAYOUT_adminhtml_STORE1_153721c655a78ae8a009d52872c6e8b7c: Please correct the XML data and try again.
2014-11-24T17:59:34+00:00 ERR (3): Cache file with merged layout: LAYOUT_adminhtml_STORE1_1a6aacbf92975cb72fbaa28e5d3264ea9: Please correct the XML data and try again.
2014-11-24T17:59:34+00:00 ERR (3): Cache file with merged layout: LAYOUT_adminhtml_STORE1_1cf9ab1b1723bedc1dcd665a812b00335: Please correct the XML data and try again.
2014-11-24T17:59:34+00:00 ERR (3): Cache file with merged layout: LAYOUT_adminhtml_STORE1_16f1b068ec7ccf4878f9284dd1137afd1: Please correct the XML data and try again.
2014-11-24T17:59:37+00:00 ERR (3): Cache file with merged layout: LAYOUT_adminhtml_STORE1_153721c655a78ae8a009d52872c6e8b7c: Please correct the XML data and try again.

[verklov]

@sivajik34, we have made a decision to not ship the Store Designer feature in the Magento 2.0 release. We are still considering the way to improve themes management in Magento 2. Please watch the repository for updates.