I’ve dealt with similar head-scratching VB6 debugger glitches before—especially when working with class modules, where the IDE’s debugging symbol table can easily get tangled. Let’s walk through targeted fixes based on common VB6 quirks that match your issue:

• First, wipe corrupted debug cache files
  VB6 holds onto old debug info that often goes bad. Start by cleaning these up:

  • Delete all *.pbd (program database) files in your project folder
  • Remove *.oca (object cache) files linked to your components
  • Get rid of backup project files like *.vbp.old
    Restart the VB6 IDE, then do a full Rebuild All (not just a quick compile) to generate fresh, uncorrupted debug symbols.

• Fix class module inconsistencies
  Since the issue ties to a class file, check for pitfalls that confuse the debugger:

  • Make sure your Property Get/Let/Set procedures are properly paired with matching signatures
  • Watch for hidden code paths in properties (like calling an unlisted Sub inside a Property Get) that can throw off the debugger’s context tracking
  • Export the problematic class to a .cls file, delete it from the project, then re-import it. This fixes corrupted project references to the class that the IDE might be clinging to.

• Audit project references and components
  Broken or outdated references (especially third-party controls) are a frequent culprit:

  • Go to Project > References and uncheck any entries marked "Missing"
  • Re-register ActiveX components with regsvr32.exe if you suspect they’re corrupted
  • Try removing non-essential components temporarily to see if the issue clears up

• Work around the crash for debugging
  If stopping the debugger causes a crash, use alternative methods to isolate the problem:

  • Replace breakpoints with Debug.Print statements to log property values and execution flow
  • Use inline Stop statements instead of IDE-set breakpoints—sometimes the inline command is more reliable than the IDE’s breakpoint system
  • Avoid stepping into property procedures directly; use Step Over and check return values via the Immediate Window instead

• Force a clean compile via command line
  If the IDE’s build process isn’t fixing the symbol issue, use VB6’s command-line compiler to bypass cached build state:

  vbc.exe /make YourProject.vbp /d DEBUG
  

  This generates a fresh build with clean debug symbols from scratch.

The behavior you showed in the video—breakpoints landing in the wrong Sub but property context showing the correct execution path—strongly points to corrupted debug symbols or broken class references, so start with the first two fixes.

内容的提问来源于stack exchange，提问作者Jason Brown