Hello, Chris.
Although it's impossible to run UWS and Cassini side-by-side, we should be able to figure out why the is not working under UWS.
UWS takes over Cassini by upgrading it: they both share same MSI upgrade code, so they can't co-exist, but UWS reads Cassini metabase (app config info) and loads and runs Cassini apps. UWS will load them into a host process that runs under Local System, .NET 2 Framework, and will run it as 64-bit, unless Cassini app was for .NET 1.1.
If your application runs as 64-bit on x64 systems, the app should have no problem.
The problem is probably something fairly simple, but we'd need to know a bit more about the nature of the failure. If you provide some details, we should be able to help.
Best Regards,
UltDev Team.
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