This is general error message for SAP analysis errors. If you are really positive that there is no SAP traffic on the wire, there is a chance that this is caused by misinterpretation of the traffic (which is detected as SAP when in fact there are no SAP frames). Version 12.2, recently released, includes major SAP decode update. I think you should give it a try.
If you sent the trace file, I could check this out, or just file a bug report.
SAP GUI 7.3 support is included since relase 12.1
SAP RFC support is included since release 12.2 with limitations
Do you have any information about SAP GUI 7.2 support ?