Update 5/3/19: You no longer need to manually update blocks as we have created a tool that will automatically update blocks for you upon editing the page.
WordPress may experience a problem with a block you’ve previously added to your page. The block will appear inactive and you will be given the options to “Convert to HTML” or “Resolve” the block. You have other options that may not be apparent to you.
Attempt to Recover the Block
First, you should attempt to recover the block which will recreate the block and the data you entered in it. To do this, click on the “ellipses” icon (three vertically aligned dots) at the top of the block when selected. Choose the option to “Attempt Block Recovery”. If this works, as expected, then you will see the new block there with all of your images and text where they were before. If this doesn’t work, then you have one more option.
Delete the Block and Recreate It
If all else fails, delete the block and recreate it. To delete a block, click on the “ellipses” icon (three vertically aligned dots) at the top of the block when selected. Choose the option to delete the block, and that will remove it from your page. Note: duplicating a broken block will just create a duplicate broken block and not a new working block with your same block settings and information.