for fabric 1.21.1 and travelers backpack 10.1.24
Can't wear the backpack when the Cobblemon: Mega Showdown mod is installed
just installing Cobblemon: Mega Showdown can cause the issue
being able to wear the backpack is what should happen
I think its because cobblemon mega showdown replaced the slot where the backpack is suppose to go when wearing it so now i cant put the backpack on

When installing Cobblemon: Mega Showdown trinkets mod is required. This makes backpack enable automatic integration and backpack can be equipped via putting in back slot like shown on the screen:

If you want to disable this integration and equip backpack via button in gui, you can do that in travelersbackpack common config: backSlotIntegration - set this option to false

oh thank you!