SASS stops working when a ship without SAS wheel decouples from ship with SAS wheel.

The ship without SAS wheel does have torque available via probe core or command module, and can be controlled manually without problems.

"prop.dev" and "deriv.dev" in attitude control go to +/- infinity, and no torque is commanded.

Not sure if it's reliably reproducable by this method, but every time this occurs, it occurs immediately after me doing that.

As a workaround, I try to select 'use stock SAS'. This does produce torque, however it causes my ship to swing wildly, like it's fighting invisible ninjas, and does not stabilise. However if I disable SASS, enable SAS in the regular way and command position manually it's perfectly happy and does not go crazy.

Not sure if related, but prop.dev and deriv.dev occasionally go to +/-infinity during normal flight, causing my ship to twitch but they sort themselves out next frame and torque resumes.

Update: It seems that having SAS ring may be irrelevant- setting the MechJeb unit as "control from here" can sort this issue sometimes, which allows normal flight but makes docking a pain!

I don't have any ships with SAS modules, or with external mechjeb modules - I added the mechjeb module to my command pods.
I'm still getting the same problem.

I got this again today with 7a5beb2 and after a bit of mucking around I found that it might be caused by MechJeb's FAR compatibility extension, as mentioned at the bottom of #187 (comment)

After removing this extension, I could no longer get a screenful of NaNs in the attitude adjustment

Closing this as an old MechJeb issue. Many MechJeb issues have had little interest in years, have been fixed for years, do not include adequate replication steps, refer to old problems which are no longer applicable, or are difficult to determine what the problem is. This issue is being closed for one of those reasons. We apologize for any inconvenience, but keeping the TODO list tidy helps the developers.

If this bug/issue is still a problem, please open a new issue. For bugs please try to include a Minimal, Complete, Verifiable Example that explains all the steps required to replicate the issue. A link to the KSP.log file should be ideally included, but is often not sufficient information. Screenshots or short videos are often the best way to show a bug.