Singleplayer worlds already created or new crash and say "locked by another running instance of minecraft" even though there aren't any other instances

Im using 1.16.1 and used fabric-carpet-1.16-1.4.0+v200623, and no it isnt i tried logging out from everywhere and changing my password but it still happens

Does multiplayer still work? I.e. are you still able to connect to any servers?

yes im able to connect to multiplayer with it just not singleplayer

Did you try the following?

• Test in vanilla 1.16.1
• Test in vanilla 1.16.2
• Test in 1.16.2 with Carpet mod 1.4.9

im sorry for the late response, i've just tested some things and it seems the issue was with another mod not being compatible with carpet
thank you for your help

What version of Minecraft and Carpet mod are you running, and is your account somehow in use by another session?