https://forum.game-labs.net/topic/19975-workaround-for-certain-ui-loading-problems-inlcuding-trader-tool/?do=findComment&comment=542624
https://forum.game-labs.net/topic/19975-workaround-for-certain-ui-loading-problems-inlcuding-trader-tool/
Check the integrity of the game files in Steam (PCM on the game, Properties->Local files)
I tried all 3 options.