Tracking down VB6 Binary Compatibility Issues with OLE View

Ever rebuilt a VB dll and find that it would no longer act as a drop-in replacement for an existing dll that has been released?

VB hides a lot of the complexity of COM implementation, and it can be rather difficult to track down how far back when binary compatibility was broken.

One way to tackle this is to use the OLE View utility, going through old DLLs build by build, and importing their Type Libraries, and Exporting the IDL files.

Then, use a diff utility to see which build has the version number was incremented, and the uuid altered.

(I’ll post some screenshots when I work out