I can see this question has been asked before but on older versions and doesn't look to be a conclusive fix.
We have our files hosted on Filemaker Server 16.
Several users have complained about the above message even on files that have been in use for a number of years with no previous issues.
I have already set the 'check spelling as you type to off' and unticked the option to 'underline questionable words'. I have also uninstalled and reinstalled Filemaker and Adobe Acrobat (as that was one of the possible causes mentioned in earlier threads) but the problem soon returns.
Closing all Filemaker altogether an reopens also seems to help but only for a short time then the problem reoccurs.
Clients use Filemaker 16 Pro on a mixture of Window 7 and Windows 10 PCs, I use Filemaker 16 advanced on Windows 10 and have had the same issue today in almost every file I have worked on.
Has anyone a permanent fix or a way to disable the spell checker altogether? My fields are mainly numerical with value lists for 90% of text inputs so spellnig is not critical for me.