Open Transaction List (e.g. Sales Order List) > Page does not Load / Unexpected Error

The error being generated is due to a custom Saved Search set to be the preferred List View. 

Users can either change the Default View that is currently used or remove the Sales Rep field from the Available Filters of preferred view custom Search.

Other option:

1. Log in as Administrator or a user who can access the Transaction List without any problem.
2. Copy the URL of the transaction list using View = Default.
3. Login using the role that is encountering the problem.
4. Paste the URL from step#2. 

Note: Defect 229381 has already been filed for this concern.