Errors during Approval Workflow of Travel Authorizations

The error shown on image below is displaying after corresponding TA has been submitted and routed to the Reviewer role and when clicking on the link to the TA from the Worklist or from the Approve Transactions page as a result Reviewer is unable to access the TA to Review it.

Then when Reviewer selected the same corresponding TA and clicks on the "Send back" button of the Approve Transaction page, a similar error shown on image below is stored on the PS_EX_SUM_APPR_ERR record and on the Errors tab of the Approve Transaction page.

We have been unable to replicate even after creating a new similar TA and we have been unable to identify a common denominator. Any feedback will be greatly appreciated.