Copy Timesheet UI Action in the Time Sheet Portal / Worker Portal generates browser errors along with page not found error.
Release or Environment
The instance was missing the "copy-timesheet-modal" Angular ng-template.
1. Navigate to "sp_ng_template.list" in the filter navigator
2. In the ID column, search for "copy-timesheet-modal"
Ensure that this record is in the instance and is not customized.