Just for anybody who will be confronted with such an upgrade, I had some issues in VB.net which were actually very small but nasty as they were difficult to find:
1. String initializations in VB 6.0 such as ... MyStr = "" .... was converted in .net to ...MyStr = Nothing ... This lead here and there to problems.
2. Business Object creation in VB 6.0 ...CreateBusinessObject(MyObject, "") ... was converted to ...CreateBusinessObject(MyObject, Nothing) which resulted in a failure of the BO creation and that turned very nasty.
3. Type conversions in VB 6.0 worked fine but not in .net. Example in VB 6.0:
Dim i as Integer
Dim dbl as Double
dbl = i 'works in VB 6.0 but results in a 0 for .net
it should be:
dbl = CDbl(i) 'a type conversion function has to be used in .net
Conclusion: This issues look simple and obvoius but I can tell you it can drive you nuts in a complex program. It took me nearly 2 weeks to debug and identify all these issues and hopefully there are no more ...
Btw. I realized that Visual Studio in the debug mode is quite instable with MSA. I had sever crashes and it is healthy to restart the application after extensive debugging.
What I also realized in the debug mode that lots of unhandled exceptions are thrown (even in a fresh unchanged MSA installation). This does not increase my confidence to the stability of the application. Also a lot of errors are displayed when the log viewer (via the analyze tool) is started. Frightening ...
If anybody has similar findings, please feel free to add comments. I will update this thread if I find out new issues.