Hey there @tithenon 
There are a few issues with v11 specifically on Forge which we are still addressing. The most notable one involves running multiple worlds with multiple Foundry licenses at the same time.
If you don’t run multiple licenses, you won’t run into that problem (multiple processes cannot access the same compendium at the same time). If you do, then you can fix it by Stopping your other game from the Forge setup screen or letting it idle before Starting a new one.
- As long as your system and modules are supported in v11, you can update to v11. Remember to take a backup beforehand!
- You can Clone your world and attempt to upgrade the clone to v11, leaving your original on v10 (by not running it). This allows you to test what will happen in a safe environment.
- Always make sure you have backup when moving between major versions. You do not, however, need to do anything like removing v10 installations. The steps in this doc should help you out
Remember, you aren’t obligated to upgrade! If you are comfortable with your campaign setup and don’t particularly need a feature that a new version of Foundry, a system, or a module offers, then you can remain on the current version until your campaign concludes, or indefinitely.
All the best, and hope this helps!