When entering the name of a Customer in either the Customer Name or Reported By AIS fields the following error is being returned: Search error: One of more errors occurred.
The error may not occur for all Customers.
This article give a possible cause for the problem and a solution.
Verify the Search Settings for the Business Objects that are being accessed by the Customer/Reported By AIS fields.
The error can occur if there is an issue with the Linked Item Preview Settings.
For example: In the screenshot below it shows that the "PrimaryEmail" field has been defined twice for the ExternalContact Business Object:
There should only be one reference to the field. Remove the duplicate and this will solve the issue.