Can't type after paste(sometimes)

If you Ctrl V in a channel then try to add text sometime it wont let you.I dont know if anyone know exact circumstances that cause this as there must be as it doesn't always happen.|||you can try to press ctr+shift once to see if you can type after that. Mind you ctrl+shift lets you select a different keyboard language (and thus keyboard layout!) pressing ctrl+shift once again will set you back to your original keyboard language and layout