Motion tracking always gives me error messages and acts unpredictably I have done my research and know that a reason for this might be that I don't have eight good trackers. However, I do have at least eight trackers in every frame of the shot, and I still get the same message everytime (some data failed to reconstruct, see console for more details). Also, where can I find the console? I looked at the python console and the info in the scripting work space, but I couldn't find anything.
I also have no idea (besides eyeballing it in the tracker preview window) whether my trackers are good or not, since the solve error changes everytime I click on solve. I have keyframe unchecked, it still changes everytime I do something. For a short periodt of time it seemed to be working just fine, I could change the weights of the trackers and managed to drop the solve error to about 1.9, but suddenly I began getting random numbers again, over 100 etc, even though I didn't change anything but adjust the weight of another tracker. Sometimes solve error equals "nan". What does THAT mean? Some trackers are highlighted in yellow, some in red when I hit A to select all (I have info turned on). First I thought it was because those trackers are the ones that failed and kept refining them, but then I realised that if I select any red tracker, unselect it and select all again it turns yellow, and others turn red. I'm so confused. Checking the tripod box doesn't make it better either. Does anyone know what I can do to get a half decent track out of this?

Also, does anyone know where I can upload the .blend file? I tried a few but the file size is about 64201KB and that's too large for most sites. I can only provide screenshots for now.



More screenshots of settings

Link to the footage I'm using: 
https://vimeo.com/419597015
(password is "tracking issue")
Everytime you get the "some data failed to reconstruct" error it means only one thing: tracking is not accurate.

Without seeing the video file is hard to determine what is wrong. Post it in some video sharing site and share the link as part of your original question. 

Vague advise is the only thing that is left until you can give more information:

If the video is blurry, shaky or has any kind of motion blur distortion you will have a hard time getting good results when tracking.

Yes, you need at least 8 good trackers,and 8 trackers means 8 solid trackers on a portion of the video where there is useful information. Use the keyframe option so that blender determines what section that is.

Check your trackers one by one on the track window to see if they are slipping or jumping about.

Example of bad tracking:



Accurate tracking:



Make sure that you are using the correct solve model. If the camera is stationary, and the camera is just panning, and tilting, but not being displaced you need to use "tripod" as the solve model, and you will get no 3D information.

There are many tools to help you figure out what is wrong(like the graphs with green, red and blue lines) use them.

Motion Tracking. What do the graphs represent and how are they useful?

There is a very detailed post in this site to help you troubleshoot tracking:

How can I get better results when doing camera motion tracking?

Read it carefuly and follow the links on that post. It makes no sense to repeat all of the info here.