Error loading block: Invalid parameter(s): attributes

I’ve used Tag Groups to create an Alphabetical Tag Index on a webpage I’ve named Topics. I used the block editor to build Topics, which only has this one block. Nothing else.

While Topics continues to work fine, in the months since I created and configured it something has gone wrong. When I open Topics in WP to change the configuration of the block, I get an error message that reads, “Error loading block: Invalid parameter(s): attributes”. I’m not a web designer. I have no idea what this means.

Since originally configuring Topics, I’ve used TaxoPress to create two new private taxonomies. And I installed the plugin Admin Columns, hoping that I could use it to sort my posts using one of the new Taxopress taxonomies. I did not succeed in the latter, so Admin Columns is now deactivated. These are the only two taxonomy-related changes made to my site since I last knew my index page to be working.

Troubleshooting steps I’ve taken:

I’ve tried creating a new page from scratch and inserting the Alphabetical Tag Index block in it. This doesn’t work either. I get the error message, “This block has encountered an error and cannot be previewed.” The new page was not cloned or copied. It was a new page with only the Alphabetical Tag Index block on it.

I’ve run Tag Group’s First Aid function in Tag Groups > Settings > First Aid > Maintenance. It found no errors. 

I am at a loss over what to do next. Are these errors familiar to anyone? Thanks.

The page I need help with: [log in to see the link]