Solving XML-sitemap error in WordPress
Although there are many threads about this subject on the internet I want to add mine too. All of a sudden I ran into this problem: the XML sitemap, rendered by the Yoast plugin, was not working properly anymore. I got the error XML parse error at Line 1, column 50.
It had worked as expected before, so I traced backed the most recent changes I had done. I had updated the theme and I changed some settings in Akeeba Admin Tools, to protect my website.
The update of the theme wasn't a problem, but the protection as set in Akeeba Admin Tools caused this problem. I reverted back to a basic .htaccess file and that solved the problem.
Then I tested all kind of settings in Akeeba Admin Tools until I identified the setting which caused this issue to happen. That did the trick, I skipped one setting, all working as expected.
So most important is when you run into these kind of problems is to check if everything is working properly with a basic .htaccess file and then slowly build up the .htaccess again.