rstudio connect error in redeploying content: change in content?

Hello, I am writing a book using RMarkdown and the Bookdown package, using RStudio running on Linux. (This happens with both Desktop and Server).

The issue is this. I can build my book fine and deploy it to the web site. But when I change something, and want to republish it, after compilation, I am told the book is being deployed, but a few seconds later I get an error. Here is what I see:

Preparing to deploy site...DONE
Uploading bundle for site: 23496...DONE
Deploying bundle: 112353 for site: 23496 ...
Error: HTTP 403
You cannot change the type of content once deployed. This content is 'static', but the bundle is identified as 'rmd-static'. Try deploying this bundle as a new content item rather than updating an existing one.
In addition: There were 33 warnings (use warnings() to see them)
Execution halted

I have no idea what these content types mean, and I haven't changed any settings in between publication. What can I do?