Call to undefined function cache_users()

First I uploaded ther wp-admin folder. This made no difference. Then I uploaded a fresh version of wp-includes folder. I checked if users in Dasboard would work but I was prompted to set up a new wp-includes file. Bit of a nightmare intially as I did not have all info required to do this asap. Luckily for me I remember I had backed up my db 2 days ago. So I uploaded the old wp-config file. I would therefore suggest backing up the wp-admin and wp-includes folders before uploading new copies. i can now access ‘Users’ from the wp dashboard.

Hope this helps anyone else who has this issue.

No idea why the issue occured in the first place.