Hello,
To sort this problem, try the following:
- delete the Hearthstone folder in C:\Users\ [username]\AppData\Local\Blizzard
- delete the Blizzard Entertainment folder in C:\Users\ [username]\AppData\LocalLow
If the problem persists we may need to check your account so please open a support ticket and include in the Description the error text “HS:CT;NetCacheDecks=0;NetCacheCollection=0;NetCacheCardValues=1”