The debugger may not break on breakpoints when you try to debug an ATL Microsoft Management Console (MMC) Snap-In on a Windows NT 4.0 computer

WORKAROUND

• Workaround 1

  Use a directory and project name that does not use long file names.

• Workaround 2

  Change the About object to use the .rgs file as shown below:
  
  
  1. Create a new registry file and edit it as follows (replacing the CLSID and class name):

           HKCR
            {
               MyClassAbout.1 = s 'MyClassAbout Class'
               {
                  CLSID = s '{22A88065-391D-11D2-8164-00C04F7948A7}'
                  CurVer = s 'MyClassAbout.1'
               }
               NoRemove CLSID
               {
                  ForceRemove
            {22A88065-391D-11D2-8164-00C04F7948A7} = s 'MyClassAbout Class'
                  {
                     ProgID = s 'MyClassAbout.1'
                     VersionIndependentProgID = s 'MyClassAbout.1'
                     ForceRemove 'Programmable'
                     InprocServer32 = s '%MODULE%'
                     {
                        val ThreadingModel = s 'Both'
                     }
                  }
               }
            }
     								

  2. Save the new registry file as MyClassAbout.rgs and import this file into your project resource. Change its id to IDR_MYCLASSABOUT.
  3. Replace the DECLARE_REGISTRY line in the About class with the following:

        DECLARE_REGISTRY_RESOURCEID(IDR_MYCLASSABOUT)
     								

  4. Rebuild all.

• Workaround 3

  Unregister the DLL and comment out the object entry for the About object when debugging.

• Workaround 4

  Use _asm int 3 or DebugBreak or ATLASSERT(0) to break into the debugger and set/re-enable your break points.