UniversalGraves is incompatible with Veinminer, as UniversalGraves uses an older version of Fabric permissions, whereas Veinminer uses the most recent one. Servers currently refuse to launch with both mods installed.

It would be very appreciated if UniversalGraves' permissions could be updated in order to fix this incompatibility.

The issue is actually the opposite (since I assume you are on 1.21.1). Veinminer released with too new (0.3.3) version of fabric permission api, which is not compatible with 1.21.1, causing a crash when certain api calls are run. 0.3.1 is only version compatible with 1.21.1

Ah, I see! The developer of Veinminer told me it was an issue on UG's end, I'll be sure to inform them!