Hi there ZBrushCentral community,
I encountered a problem after installing a bunch of MatCaps into the ZBrush MatCap folder:
C:\Program Files (x86)\Pixologic\ZBrush 4R4\ZData\Materials\Startup
I tried to restart ZBrush to access the newly installed MatCaps but it won’t start anymore. So I tried deleting the MatCaps but it didn’t solve the problem. 
Is there any kind of temporary or startup data that I have to delete to solve this startup issue?
thanks in advance