PyRevit Generate Revision Report Error

[Robbo1234]

Describe the bug
PyRevit Generate Revision Report doesn't display revision bar chart.

To Reproduce
Steps to reproduce the behavior:

1. Go to PyRevit Generate Revision
2. Click on PyRevit Generate Revision Report
3. See error screenshot

Screenshot

Desktop (please complete the following information):

• OS: Window 10 Version 1809 (OS Build 17763.379)
• pyRevit Version 4.6.24
• pyRevit Environment: Open a command prompt and run the command below. Replace these lines with the results. Take a look at this markdown guide and wrap the command results in ``` when pasting here for correct formatting.

pyrevit env

:\Users\rob.cross>pyrevit env
==> Registered Clones (full git repos)
==> Registered Clones (deployed from archive/image)
master | Deploy: "basepublic" | Branch: "master" | Version: "4.6.24" | Path: "C:\Users\rob.cross\AppData\Roaming\pyRevit-Master"
==> Attachments
master | Product: "Autodesk Revit 2020.0.1" | Engine: 277 | Path: "C:\Users\rob.cross\AppData\Roaming\pyRevit-Master" | Manifest: "C:\Users\rob.cross\AppData\Roaming\Autodesk\Revit\Addins\2020\pyRevit.addin"
master | Product: "Revit 2019" | Engine: 277 | Path: "C:\Users\rob.cross\AppData\Roaming\pyRevit-Master" | Manifest: "C:\Users\rob.cross\AppData\Roaming\Autodesk\Revit\Addins\2019\pyRevit.addin"
master | Product: "Autodesk Revit 2018.3.3 Security Fix" | Engine: 277 | Path: "C:\Users\rob.cross\AppData\Roaming\pyRevit-Master" | Manifest: "C:\Users\rob.cross\AppData\Roaming\Autodesk\Revit\Addins\2018\pyRevit.addin"
master | Product: "Autodesk Revit 2017.2.5 Security Fix" | Engine: 277 | Path: "C:\Users\rob.cross\AppData\Roaming\pyRevit-Master" | Manifest: "C:\Users\rob.cross\AppData\Roaming\Autodesk\Revit\Addins\2017\pyRevit.addin"
master | Product: "Revit 2016" | Engine: 277 | Path: "C:\Users\rob.cross\AppData\Roaming\pyRevit-Master" | Manifest: "C:\Users\rob.cross\AppData\Roaming\Autodesk\Revit\Addins\2016\pyRevit.addin"
master | Product: "Autodesk Revit 2015 Release 2 (Subscription only release)" | Engine: 277 | Path: "C:\Users\rob.cross\AppData\Roaming\pyRevit-Master" | Manifest: "C:\Users\rob.cross\AppData\Roaming\Autodesk\Revit\Addins\2015\pyRevit.addin"
master | Product: "Autodesk Revit 2014 Update Release 3" | Engine: 277 | Path: "C:\Users\rob.cross\AppData\Roaming\pyRevit-Master" | Manifest: "C:\Users\rob.cross\AppData\Roaming\Autodesk\Revit\Addins\2014\pyRevit.addin"
==> Installed Extensions
==> Default Extension Search Path
C:\Users\rob.cross\AppData\Roaming\pyRevit\Extensions
==> Extension Search Paths
J:\Revit Plug-ins\pyRevit\pyL_R-master
==> Extension Sources - Default
https://github.com/eirannejad/pyRevit/raw/master/extensions/extensions.json
==> Extension Sources - Additional
==> Installed Revits
Autodesk Revit 2020.0.1 | Version: 20.0.1.2 | Build: 20190412_1200(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2020"
Revit 2019 | Version: 19.2.20.24 | Build: 20190808_0900(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2019"
Autodesk Revit 2018.3.3 Security Fix | Version: 18.3.3.18 | Build: 20190510_1515(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2018"
Autodesk Revit 2017.2.5 Security Fix | Version: 17.0.1169.0 | Build: 20190508_0315(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2017"
Revit 2016 | Version: 16.0.1218.0 | Build: 20190508_0715(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2016"
Autodesk Revit 2015 Release 2 (Subscription only release) | Version: 15.0.1103.0 | Build: 20140905_0730(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2015"
Autodesk Revit 2014 Update Release 3 | Version: 13.11.4 | Build: 20140709_2115(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2014"
==> Running Revit Instances
Error: Access is denied
Run with "--debug" option to see debug messages

[eirannejad]

Merged into #656 to be taken care of together