I was getting "Solver failed" messages last night. Using "--no-verify --no-plots --no-fits2fits --resort --downsample 2 -O" which I think has worked for me in the past. (I am using the Offline solver)
Do I need to have "Solver: Enabled" selected in the INDI Control panel > camera_being_used > Astrometry section? I would test it now but it's the middle of the day.
Turn on verbose astrometry log in Configure KStars --> Ekos --> Modules --> Astrometry.net, this would display complete log of astrometry.net and will display why it failed
With the debug option set correctly, I can now see that one of my solve-field flags had a typo. Now everything is working like it should. Thank you for pointing me in the right direction!
The following user(s) said Thank You: Jasem Mutlaq