First let's test the connection between your radio and the OS2:
- Set the Null connector's modem mode to D-STAR, set the frequency and click on the Save button
- Activate the Null connector by click on the Switch to selected button at the top of the Connectors page
- Set the URCALL in your radio to .......E (seven spaces and an E). Press PTT on your radio and say something, and then release the PTT. Do you hear yourself back?
If yes, set the URCALL back to CQCQCQ, and use the Quick Setup to connect the OS2 to a server. A valid D-STAR registration is only needed on old DCS and REF/XRF servers like REF001 or REF030. Usually the server accepts your connection, but you won't be able to transmit on the server.
You have to log in to the server where you've made the registration to fix it. You can find the link to the registration server on the registration check page:
https://wb1gof.dstargateway.org/cgi-bin/dstar-regcheck?callsign=ki5dzu