I am getting this same error. I can’t use FTP because my host doesn’t allow it (Good Gallery)
whew, thank you so much for your help Jess and ClaytonJames. My site is now back to normal. After trying all your suggestions, with none of it working, it made me think that the problem lie somewhere else other than my theme.
When my original code edits didnt work and I got the error, I went to replace the functions.php with my back up copy, but I stupidly replaced my wordpress functions.php file, and not my theme’s functions.php file. This messed everything up and was why I could not login to WP-Admin even though I deleted my themes.