Note: These might or might not be fully or partially fixed by now, these have been found early on after the launch.

-Not being able to equip items:
Drop the item stack from inventory and pick it back up again.

-Not being able to pick up currency items:
Drop your last passive buff item (bottom row) and do not pick it back up again.
(Maybe caused by having a full row, so if true, you could drop any passive as long as you're not full.)

-Not being able to throw a Pipebomb/Grenade:
If it happens, switch to a different weapon and back to your grenade, possibly try not having your flashlight out.

-Stuck in (Medkit/Item) animation, not being able to sprint, switch or use anything:
#Let yourself get hit by a zombie once, use the (Medikit/Item) again, it should be fixed.
(Possibly could happen with different items, when the animation gets interrupted.)
#Alt. way by Otacon815: Switch that item out with another by holding your interact key over that new item and switching out the stuck item.
#Alt. way by KanoBoii: Vault over something.

-No running animation, being stepped/stuttered forward, not fluently:
Generally fixes itself shortly after it happens, try climbing something.

-Being stuck in codebook:
Possible use of screenshots, has not happened to me yet, but I saw others having issues.
Try not to use the codebook or as rarely as possible, if this has already happened to you, maybe use a screenshot in the future. If the codes do not change (i don't know yet) make one once, if they change make a screenshot once per round and put it on your 2nd monitor if available.
(Maybe try rebinding your use key to a different button.)

#By alias
-Keybinds not working at all for some non US players:
If you use a non US keyboard layout, try changing the layout in Windows to English (United States)