The following error happens when an empowered cast happens on friendly nameplates:
StatusBar:GetRight(): Action[FrameMeasurement] failed because[Can't measure restricted regions]: attempted from: StatusBar:GetRight()
It could happen on enemy nameplates too but I haven't checked.

The error is caused by

Changing the line to local elementWidth = element:GetWidth() seems to work fine.

Thanks for the report, didn't think to test on friendly nameplates.