Dittos when with other mods or standalone

crash-2019-06-22_16.54.03-client.txt

This is likely due to wrong versions.
Which Backpack version do you use? UTeamCore version? Forge Version?
Try to update everything to the newest.

I was on 1.14.2 using the 1.14.2-1.7.0.27-SNAPSHOT Forge version, launched with the Forge ModLoader. I realize now I also didn't have the dependency, I'll try again with the dependency on .28 and see if that works, and update here.

Your forge version is too old.
Please use at least 1.14.2-26.0.43

crash-2019-06-22_20.04.12-client.txt

Using only u_team_core-1.14.2-2.5.3.114 and useful_backpacks-1.14.2-1.7.0.28

Yeah, no crash on .50, thanks. Not sure how I would have gotten such an old version having downloaded like last night, but I wouldn't have considered checking that. Thanks!

No problem :=)
Currently forge is changing and updating very fast so it is nessessary to update very often.