Bob, I received this error early this morning. The script halted and the observatory did not shut down as it has done before. Any idea what might have happened?

Jerry Gunn

08:32:25 (final exposure interval 6.11)
08:32:25 [T] [stpgdr] SelectStar is False, refinement pass, use previously selected star.
08:32:25 [T] [stpgdr] Starting exposure is 6.11 sec.
08:32:42 [T] [stpgdr] Guider detector is 657 by 495 pixels in size
08:32:42 [T] [stpgdr] Use star at [644.6,216.2]
08:32:42 [T] [stpgdr] Found at [644.9,216.5]
08:32:42 [T] BGRMS=2849 StFlux=6939 SNR=2.4
08:32:42 [T] New exp=7.53
08:32:42 (guide star SNR=2.4 X=645 Y=217)
08:32:42 **Script Error (Tracking has been stopped)**
08:32:49 Source: MaxIm DL 6
08:32:49 Message: Bad input parameter
08:32:49 Location: line 1712 column 29.
ACP console log closed 23-Sep-2015 08:32:49 UTC

The offending command from the AcquireImages script is:

// The cause of guiding failing to start could be because
// pointing is not "perfect." If using an internal/OAG guider,
// do a pointing update, then try to start again.
if(!SUP.ExternalGuider && Prefs.PointingUpdates.Enabled)
Console.PrintLine(" Doing pointing update to assure guide star on internal/OAG chip");
isPointing = true;
SUP.UpdatePointing(Tc.Name, Tc.RA, Tc.Dec, Tc.PA);
isPointing = false;
SUP.AutoGuide(true); // Try again