You can fix it with the following two things:
1. Go to your cpanel main directory where your site exists.
Then right click on the “.htaccess” and then rename it to something
like “.htaccess_old”.
When your site get ready then again rename it back to the “.htaccess”
2. Go to your Cpanel >> File Manager >> yoursite folder >> wp-content >> and then
rename “plugins” to “plugins_old”.
When your site get ready then again rename it back to the “plugins”
And after that activate your plugins one by one and see which one is creating this
error and deactivate and delete that …
If you have any further issues then give your kind feedback.
Thanks & Regards,
graphypro