I also have this problem but i have a work around for it.
Step 1)
Using PHP MY Admin go to the xxxxx_extensions table and find the record "PLG_SYSTEM_BACKUPONUPDATE_TITLE"
Edit this record and change "Enabled" from "1" to "0"
Step 2)
You may also need to clear the Administrator Cache
Using FTP or cPanel File Manger navigate to /administrator/cache and delete all the sub folders
Note : I have found this problem on 3 websites so far and the only other common item is they are all running MIJO Shop as well so i'm not sure if its an Akeeba Backup or Mijo Shop issue but disabling Backup on Update will get the back end going again. :)
Step 1)
Using PHP MY Admin go to the xxxxx_extensions table and find the record "PLG_SYSTEM_BACKUPONUPDATE_TITLE"
Edit this record and change "Enabled" from "1" to "0"
Step 2)
You may also need to clear the Administrator Cache
Using FTP or cPanel File Manger navigate to /administrator/cache and delete all the sub folders
Note : I have found this problem on 3 websites so far and the only other common item is they are all running MIJO Shop as well so i'm not sure if its an Akeeba Backup or Mijo Shop issue but disabling Backup on Update will get the back end going again. :)
