Hi Malinda

My suggestion is to try and identify if it is one of the third party plugin causing this by disabling all the third party plugins and seeing if this error occurs. If it does then enable the plugins one by one to identify which plugin may be causing the problem.

It is possible that a setting has changed in Totara that the third party plugin is modifying.

The developer logs for the upgrade should outline any incompatibility issues.

regards

Craig