I just had the similar problem today, loading for a flightplan from OKKK (Kuwait) to LTBJ. Because Kuwait had changed their ICAO from OKBK to OKKK I had some trouble getting together an original fp and could not enter anything from Simbrief, just at the FLT OPS STS and the LOAD SHEET. In the INIT it showed me not "FROM"TO", more like "CPNY RTE" both ICAOs side by side, nothing more, no flight nr. Even the datas on the other pages were not loadable.