If your cards are blank upon reviewing. This typically means that you have encountered a 1-by-1 card with a missing cloze.
To solve this issue:
- Navigate to Tools
- Click on Empty Cards
- Click Delete (leave the box ticked)
If this does not solve your issue, this means that you may have accidentally protected your Text field on AnkiHub.
- Find the deck on AnkiHub
- Navigate to the 3 dots on the top right
- Click on Manage protected data
- Uncheck the text or extra field
- Save Changes
- Go back to your Anki desktop application
- Reset your local changes by going to browse → click on AnkiHub at the top → reset local changes