IIS still ships the Classic ASP runtime, so a twenty-five-year-old VBScript application keeps limping along: no debugger, no tests, no dependency management, and a security surface from another century. Because it never quite dies, it never gets budget, until the one person who understood it leaves.
I migrated a music-rights royalty system and a twenty-year Billboard chart archive off Classic ASP, the second one to Blazor on Azure, with the business publishing throughout. The approach is the same every time: get the database somewhere safe first, stand the new application up beside the old one, and switch pages over one at a time. Where the old code has no documentation, an LLM-assisted pass with a confidence score on every record finds what the code actually does faster than reading it.
Silverlight has no runtime left. The exit is screen by screen, not a rewrite.
LightSwitch generated your app. The tooling to regenerate it is gone.
Your records are in Notes databases. Getting them out is the job.