Global GK settings lost

[rcknrllmn]

  It seems I have lost all of my global GK settings.  At my gig last night before soundcheck, I switched one of my guitars & went into my settings and all of my settings for my 4 guitars were set back to factory default.  I've had these settings in there from the beginning for many many years. 

  Has anyone ever had this happen?

  Anyone have any recommendations?  Is there a system memory battery I should change, or is this some kind of an anomaly?

Thanks

[gumtown]

No internal battery according this post
\https://www.vguitarforums.com/smf/index.php?topic=16755.0

Gig time seems to be a special time for some things to misbehave or stop working,
 and later, when you look at the gear the next day, and all seems good again (mysteriously).

So the settings are today still missing/defaulted ? 

[rcknrllmn]

Just checked, still gone.  It did save my quick settings changes from last night.  I really only changed the scale from St to LP to get through the gig.  I was keeping my fingers crossed.  My main LP was fine.  I was glad I did not have to switch to the backup guitar because it made my patch levels all over the place for acoustic/ clean very low compared to patches with OD/& more gain.