CommonDialog was not a loaded control class.
 
Loading Visual Basic 6 (VB6) projects, sometimes the following error is received:
 
Errors during load. Refer to 'c:\files\myform.frm' for further details.
 
In the log file the following entry is found:
 
Line 50: Class MyComDlg.CommonDialog of control CommonDialog was not a loaded control class.
 
I dread it when I get this error. I used to remove the common dialog control from the form to add it again. That solved the problem. However any settings made in the VB6 designer's property panel were lost. You can fix that again by not making the settings there but to write it into the source code.
 
The easier solution to fix this problem is to edit the .vbp project file. For some reason VB6 puts a reference to the common dialog ocx into the vbp file. Example:
 
Reference=*\G{A9446BDD-FEF1-43D7-B1BE-B089757C016A}#1.2#0#C:\WINDOWS\System32\CO
MDLG32.oca#Microsoft Common Dialog Control 6.0 (SP3)
 
Just remove this line and save the vbp file. Making a backup copy of the vbp file before doing this is not a bad idea!