VB6 calling .NET 4.0 DLLs on a network share

I have a VB6 app that calls a number of .NET DLL's, all that reside in the same folder. Until recently, the .NET DLL's all used Framework 2.0, and I used CASPOL and REGASM to trust and register the DLL's for use by the VB6 app.

I recently converted to .NET Framework 4.0. Everything works fine when the app folder is on the local HDD but will not work when it resides on a network share. REGASM returns 0x80131515 ("Operation is not supported"). I've Googled this and read up on the 4.0 security changes, but I haven't found a work-around. Nothing seems to mention the VB6=>.NET problem. I added this line Assembly: Security.SecurityRules(Security.SecurityRuleSet.Level1) but it didn't make a difference.

You should be able to debug the C#.NET dll by setting the start action under Debug to

Start external program

and specify the VB6 executable as the program.

I know this works as I use this to debug a .NET/C# plugin for an old VB6 application.

It shouldn't matter how many other dlls (.NET or otherwise) you have to go through to get to the code you are trying to debug.