I think are are not understanding what I was highlighting in my message. Particularly where it says "IMPORTANT" - it states that every time you run the Save on the Modify Valheim+ Config tool your valheim_plus.cfg will be overwritten and the settings from that tool only will be applied (and anything made changed via FTP will be ignored and overwritten - the two don't work in concert and are not interchangeable)
Also you can't change the Max Players because you didn't pay for it. I just looked you up, you paid for 10 slots. That means you get 10 players only and are not permitted to add more slots. If you upgrade to more slots you will have the ability to modify the max players input on the Modify Valheim+ Config tool.
Correct, that is how the tool functions in the event that you save within the Modify Valheim+ Config tool.
Outside of this tool your valheim_plus.cfg will not overwrite.
We don't need an Incompatible Version topic every time a patch is released. If you have this issue and can't figure it out using the pinned threads here, create a support ticket.
Yes via the backup restore on the panel.
Clean Save World to wipe and create a new one (diff seed) and then you can roll back to the old save using the tool on the panel.
Because that's not how the game is designed. There is no server-side generation or configuration for seed.
You are free to generate one locally and then upload though as has been stated.
We'd like to take a look at this via support ticket - please reach out so we can take a look.
EDIT: Found your game server and ran a Verify on your game files, fixed the issue.