Still experiencing "Sync Token Is Invalid...." error message? Anyone know?

[WillowMobileSys]

We continue to experience an issue that seems to occur each time we push out app updates.   On each re-deployment there is at least 1 user, sometimes multiple users. who gets the error while all others do not.

We tend to push changes in the evenings, so users begin experiencing the errors the following work day.  Some users get the error as sson as they begin using the app.  Others can use the app for a good portion of the work day beore they see an occurrence of the error.

Does anyone know the casues these "Sync Token Is Invalid...." error messages for only a few users and what we can do to prevent it?

[AleksiAlkio]

Is this happening for the same users or randomly? Laptop or mobile? Is the app big? How long is the sync time?

[WillowMobileSys]

Different users each time.  All on mobile devices.  It's not a big app.  We have the Security Filters well tuned and designed to make best use of database side filtering so only a few hundred rows are downloaded for each user.  The Sync times are running around 10 seconds.

But I don't think the users even get to a Sync when the error happens.  They will open the app (no login) the day after the app push and access a Punch In function.  As part of that Punch In process we did try using a force Sync to ensure an updated app.  But it seems they get the error before that.  This is when most of the impacted users (about 1-3) hit the error.

We have had a couple of occurrences of users who log in and use the app but then hit the error much later in the day.  But it seems like their app version did not update - as if the force Sync didn't work.

I tried this myself on my mobile device.  I hadn't accessed the app in a while.  But today I was able to get into the app AND the latest version was updated onto the device without me having to tap the Sync button.   it worked as expected.