MC 1.19.2
Inspecio 1.6.0
NPC Variety 2.2.1
Wanderer's Catalogue 1.0.0

To reproduce install all 3 mods and hover over the wandering trader's spawn egg in creative menu.

Might be similar to: Queerbric/Inspecio#61 and Queerbric/Inspecio#33

Removing any of the mods fixes the issue.

Logs: https://gist.github.com/Footage2-Amply-Pounce/0edc4e079ad7941cc73d3883df76740f

Spawning wandering traders produces a crash as well. Likely to be fixed on Wanderer's Catalogue's side: AmyMialeeMods/wandererscatalogue#1 (comment)

Will keep this issue open for awareness until then.

Fixed.