Application Exception: Invalid Class – when using eDrawings or PDM Preview – Hawk Ridge Systems

When using eDrawings or the PDM Preview tab you may see Application Exception: Invalid Class. As this is generally caused by a Windows issue, repairing SOLIDWORKS, eDrawings or PDM will normally fail to resolve the issue. The following article will walk you through fixing this error by repairing the damaged part of Windows.

The PDM preview and eDrawings will fail to load anything and you will get the message "Application Exception: Invalid Class." The viewing area will either remain blank or you will get a spinning circle rather than an image of the file. This happens generally because the Windows Management Instrumentation is damaged

Repair the Windows Management Instrumentation using Administrative Command Prompt

First, confirm that the Windows Management Instrumentation (WMI) is damaged by using Run (Win+R) and enter "wmimgmt.msc"
Once WMI is open, right click on the WMI Control (local) and select properties
If the WMI is damaged you should see "Failed to initialize all required WMI classes"
Now that you have confirmed the damage, open Command Prompt with Administrative Permissions
Use CD to change directories and step into C:\windows\system32\wbem:
CD C:\windows\system32\wbem
Copy the text from the attached "Commands to repair WMI.txt" or copy the commands listed below into notepad, then cut them from notepad (this will remove formatting that may prevent the commands from working correctly) and paste into Command Prompt:

regsvr32 /s %systemroot%\system32\scecli.dll
regsvr32 /s %systemroot%\system32\userenv.dll
regsvr32 cimwin32.dll
mofcomp cimwin32.mof
mofcomp cimwin32.mfl
mofcomp rsop.mof
mofcomp rsop.mfl
for /f %s in ('dir /b /s *.dll') do regsvr32 /s %s
for /f %s in ('dir /b *.mof') do mofcomp %s
for /f %s in ('dir /b *.mfl') do mofcomp %s
regsvr32 wmisvc.dll
wmiprvse /regserver
You may get a couple pop ups confirming dll registration, click ok in those. When done go back and confirm your WMI properties now show "Successfully Connected to"
Open eDrawings or the PDM Preview Tab and your file should now render.