Can someone assist me on why I don’t get any map tiles when running the osmctrlapp.exe program? I have tried selecting OSMARENDER and MAPNIK under PROVIDERS.

You’ll need to ask whoever provided the software that you’re using. I’ve never heard of it, but a quick web search finds this: https://github.com/fatelancer/IEC104PowerFlow - maybe that’s related to what you are doing?

Someone’s also just now added this question on the OSM help site: https://help.openstreetmap.org/questions/68079/german-umlaute-aou-etc-no-longer-supported .

If it offers “OSMARENDER” as an option it’s probably pretty outdated software. Osmarender hasn’t been maintained since 2012.