[itsme]

What a silly misunderstanding!

I understood the first window as "Ignore Update Yes / No" with pushing Yes as "yes, ignore update" = do not update, see my very first post in this thread.
In fact there are three choices 
"Ignore Update" = do not update and don't ask again
Install "Yes" = update
Install "No" = do not update, ask again on next start

So now I have another question: to find out what I wrote above I clicked "Ignore Update" and have now 3.8.25. How can I initiate the update to 3.8.26 again?
In MobileSheets Settings - About there's an item "Check for Update". If I click that, it says "No Update Available" which is wrong, I'm on 3.8.25 and 3.8.26 is definitely available.
Neither restarting MobileSheets nor restarting the tablet helps.
Uninstalling and installing again will probably install the latest version 3.8.26, but I keep it as is for the moment, just in case we need that state for further investigation.
And I kept a backup of 3.8.25.apk so that I can re-install that again if necessary.