This block contains unexpected or invalid content – Issue and Solutions

While you try to edit existing post/page content, sometimes you may face the error
This block contains unexpected or invalid content.

Please follow this process to fix this.

1. Click on the ellipsis icon at the top-right of the block
2. After that click on Attempt Block Recovery
3. The block will be fixed

For Advanced Columns, you may need to proceed furthers

4. Click on Update ( Update the post )
5. After Update, Refresh the edit screen from the browser