Ron, use this, it's what I use works perfectly.
Download the new Raspberry Pi Imager, onto your PC or MAC, use it to burn an image of the Raspberry Pi OS 32 onto the sd card. Connect a LAN cable, HDMI monitor, keyboard & mouse to the Raspberry Pi insert the sd card & power it up. Let it set up, after that follow the instructions here github.com/rlancaste/AstroPi3 to install the AstroPi3 script. Then you'll have a working system with the new StellarSolver already installed. Then use the script in the utility folder to install the solver index files to suit your imaging set up & don't forget to change the telescope details in the simulators to match those of your own telescope after you've installed the indexes. You'll then have a working system.
Set a bit of time aside as the build using the script takes a while but it's well worth it.

good luck

Alan

Please add information about missing index files, and maybe a little hint how to download/add them. Now there is only message about solving fail. Without this forum it would be hard to even find out that something like "index files" are needed for newbies like me

Just an update, I moved up to an Rpi 4 with 8 Gb Ram (the previous one was an older one with only 1 Gb), seems to have cleared up most issues with solving. Ok, I don't really know it is related as I am now also running the latest Raspbian OS and Kstart 3.5.0. I get fast solves, especially with my wider FOV finder scope (ASI120 on an Orion 9x50), but also using the main camera (9.25SCTf/6.3 and ASI533)with a much smaller FOV, even around the pole. I can use the main scope for my second polar align to get very close.

Great work on this project!
Ron

I did actually add messages in KStars and in fact if the user has no index files, I set it to open the index file download dialog automatically if they try to solve. But if you don't have the latest KStars beta, you won't have that.

Great news ! While it is great to have that function builtin, actually I have a thought that making it default to "online astrometry" with message - if you want it faster use "internal solver" would be good idea.

That is another possibility

damn it, so maybe distro makers like Astroberry and packagers should do "apt install astrometry-data-2mass astrometry-data-tycho2" requirements/suggest to their packages ? other way - make internal solver not default on those distros beside of default libindi

Well your idea of just making the default the online one is the best of what you have said. I wouldn't recommend having a whole set of index files as a requirement for an install. It is very important that the user only downloads the index files they need. Index files are huge. And it is very difficult to predict exactly what the user will need. They need to decide that for themselves.

Thats exactly what was in my mind. APT and rpm packages have its "recommended" feature. It should be more up to packagers/distromakers to keep things the most user friendly as possible. Thank you for reading

There is one little issue with solver settings interface. When I downloading index files and run out of storage space, GUI do not inform me about this. In fact it just making 0 size files and mark index files green/checked

I had two Kstar crashes tonight associated with the solver. Both were in the process of Polar alignment. the first crash occurred at the third solve, the second crash occurred at the first solve. the logs give no clue as to what happened, they just end. I am including the beginning of a log and the two tail ends of the logs that just stopped. This seems random, as just a couple of days ago I had no problem with PA using the same procedure. I do a PA using a wide angle scope going West (manual slew) and then after adjustment I do a second PA going East (manual slew), when I am done it seems that I am within a couple arc minutes. The last time I ran the routine I got thru them fine. Tonight I almost got thru one routine and it crashed, after restarting it crashed again at the beginning of the PA routine. Is there a debug log for the solver? If so I did not have it turned on, as the solver has not given me any problems in the last several outings.

I doubt I can repeat these failures, but let me know if there is anything I can provide.

Ron

So this is not actually related to the Solver, but to KStars' Index File Downloader. I did write that several years ago, but technically its not a part of the solver.This would be a good thing to add for the future.