ITEM IS NOT ALLOWED FOR THIS HERO. any item cant be purchased... when it hit 30 min mark

sample match. match id 2251111780. i was clockwerk. any item i tried to buy, from tp to recipes didnt work. was showing the error message in the game ITEM IS NOT ALLOWED FOR THIS HERO. when the game was at the 30+ mins, i cant buy anything... as in ANYTHING. this was my 3rd game for the day and then that bug happened.