Also, it should only be a few lines down. Good luck.
If you are desperate for it to work and do not care about validation: go into your file manager/ftp to edit your files. Navigate to the admin folder and edit the file that is named something like “admin-header.php” (I can’t recall if this is exact) and remove the doc type which looks something like “<!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Trans//EN”
“http://www.w3.org/TR/xhtml1/DTD/xhtml1-Trans.dtd”>.” Once again, this isn’t exact. Let me know how this goes.
Hmm found the issue, but will be needing lots of help. I edited the header information (removed the xml lang and document type.) This means I’d have to go through every file and remove that. No good.
