After upgrading, I get an error about a blank line causing problems with the plugins for UpdraftPlus and Yoast SEO.
Updraft gives me this error “Warning: Your WordPress installation has a problem with outputting extra whitespace. This can corrupt backups that you download from here.”
Yoast gives me an error when I try to view my sitemap.xml file. “This page contains the following errors:
error on line 2 at column 6: XML declaration allowed only at the start of the document
Below is a rendering of the page up to the first error.”
I installed a plugin that disables everything, then I started turning plugins back on, and when I turned on Buddypress, the error started happening again.
Here is the article on the Yoast website that explains the plugin I used for troubleshooting.