Thanks to Peter Walker and Gili Mendel for helping me resolve this. I have a (somewhat) unique demonstration environment, with multiple Rational products installed locally, include RAM and RRC, which both have their own RTC servers. I installed RAM first and then RRC and likely clobbered my RAM RTC developers license. That was why I received the error when trying to submit an asset, which in turn attempts to create RTC work items and that could not happen because the license was invalid.

The resolution was simply to go to the Rational License Key Center and download a RTC developers CAL. After unzipping that, I went to the RAM RTC Admin Gui, License Key Management and added the new developers license. Worked like a charm!