My end user tried to tun her end-of-day UPS processing, and initially got this error:
Unable to process "End of Day" request. Upload error: Upload PLD transaction failed: Internal CMSHTTP Error [9999]

She can still see the one UPS shipment that needs to be processed. She is not able to deleted the shipment, and if she tries to do the EOD processing she gets:
No shipments to process for the current day. Upload of prior days' data complete.

Reboot did not fix the problem.

Using version 3.0.0.574