I resolved by uninstalling both versions, then doing a fresh install of 2. 17. But, I didn't have any data to lose as both were new to me, so that wasn't an issue.
After installing 2. 17 clean, I saw the blob error one time. I refreshed the page, logged out, logged back in, and haven't seen it since.
I have no idea what that's about, but since it seems resolved, I don't worry about it.