Can't open upgrades menu in MvM
Solution 1:
According to this Steam community thread, it's possible to fix this bug by pressing the "inspect" key (F key by default), closing the box that appears and walking up to the upgrades bench again.
According to this Steam community thread, it's possible to fix this bug by pressing the "inspect" key (F key by default), closing the box that appears and walking up to the upgrades bench again.