OK, I've just tested with version 1.2037 and with your profile.
What I see is you using Gerry's 2017 screenet.
I do not have the latest version from Gerry, so I can't test with that screenset at the moment.
What I could do is I've changed the screenset to the Default one in your profile and then I enabled the C axis and Applied the settings and then Calibrate ... it works OK.
What I think is that the issue is screenset related, because the core software and default screen does not seems to have this problem, the C axis enables fine when using your settings.
Please ask Gerry to verify this issue in the screenset. Or I'm sure he will read this thread soon and will check it out for you.
And version 1.2045 is the latest development release it is not an official version yet, but we always using the latest dev. version for testing when possible,
because that version is what may become the next official release, so correcting any issues will happen in the latest dev. version.
Here is the forum thread with the UCCNC releases:
viewtopic.php?f=2&t=240&start=40