Hi,
Because of the multiple errors in, what appears to be your version of Essential, my advice to you would be for you to uninstall this theme completely. See Installing add-ons#Uninstalling an add-on.
Once this is done all the settings you had for this theme will be deleted, and it is this that is important in your case, as you need a blank canvas to start over. Yes it is tedious, but if you want it to be right you have to do it right.
After this you will also need to remove that theme from your server, as it cannot normally do that because of the of server the read/write/execute permission set. It is important that you remove that theme as it sounds like it has been corrupted.
After this has been done you will need to Purge all cache. Again this step is very important!
That done you now need to get yourself a fresh copy of the Essential theme. The latest version can be found HERE
Unzip this file to your desktop and make sure you find the essential theme folder (you may have to rename this folder to 'essential' rather than the long name that it may have) inside the extracted folder, which at this point will be called something like 'moodle-theme_essential-master'.
All being well you can mow upload this 'essential' theme folder to your Moodle/theme/ directory on your server. Once that is done go to Notifications and install it by following the instructions given.
Please let me know how you get on?
Thanks
Mary
