Thank you for your post.
When you installed FileMaker Pro, the main spelling dictionary should have been put into the FileMaker Pro -> Extensions -> Dictionaries folder. If the dictionaries are not there, then reinstall FileMaker Pro.
I'm using my filemaker 10 for a long, one afternoon when I'm entering new record to my fields suddenly it pop up that problem.
Some diagnostic questions to investigate:
Does this happen only with one specific file? If so, the file may be damaged.
Does this happen with all files on this computer? If so, TSGal's suggestion is a good bet to solve this issue.
Thanks to TSGal's & Philmodjunk,
I found the solution, in the File, File Options,I uncheck the "Indicate Questionable words with special underline" and it works.
I wouldn't trust that "fix".
You shouldn't get the error message you are getting just because that option is selected. The error message is telling you that something is wrong with either your file, your computer or your installation of Filemaker. If you don't correct it, other problems may ambush you when you can least afford to deal with it.
For example, if your file is damaged and you continue to use it as is, you could at any time experience a more serious issue like missing data, filemaker crashes, etc.
It gave me this error also after installing a fresh copy of FM Pro Advance 11. I uploaded the dictionary from my old FM Pro Advance 10 that I had in my laptop and everything started working just fine. So, in my case it was a dictionary issue. Try using a different. Contact me if you would like a copy of mine.
I hope this helps!