Solve all compiling error using the followings:
1)In gradle-wrapper.properties update gradle to "4.8-all.zip"
2)In build.gradle (project) update gradle build to 3.2.1 &
in rootProject.ext{...} add SupportLibrary = "26.0.2"
i.e;

rootProject.ext {
......
SupportLibrary = "26.0.2"
}
3)In build.gradle(app) add following lines:

configurations.all {
resolutionStrategy.eachDependency { DependencyResolveDetails details ->
def requested = details.requested
if (requested.group == 'com.android.support') {
if (!requested.name.startsWith("multidex")) {
details.useVersion rootProject.ext.SupportLibrary
}
}
}
}
&
update dependency of wallpaperboard library
i.e; implementation 'com.github.danimahardhika:wallpaperboard:1.7.0-b5'

check this link:#141 (comment)