Error Message: "Cannot load main spelling dictionary"

How can I remedy the following Error Message: "Cannot load main spelling dictionary".
Do I need to restore a FileMaker Pro (or any other) Dictionary File and if so, what Filename do I search for?

Mac or Windows? Do you use BitDefender anti virus, as there have been problems with this in the past causing this problem.

Also, what are your preferences within Edit -> Select Dictionaries?

Regards
Andy

By the way, to answer your direct question, please have a look at: Can't load main spelling dictionary

Using FMP15 for Windows 10 Pro OS Build 19041.508.
Anti-Virus software: Sophos Endpoint Agent 2.10.7.
I tried disabling the Spelling Checker by changing the setting in File Options by unTicking the TickBox "Indicate questionable words with special underline". However, this Tick is always there, regardless of what I try - unTicking doesn't work.
I have copied the File "KLBD_Dictionary" (this is a personalised version of the default Dictionary File) with the Type of File: "FileMaker Pro Dictionary (.upr)" and the message stopped popping up!
Thank you for trying to help!

If this has met your requirements, I’m glad to hear this.

We also use Sophos Endpoint on our desktops and servers (and have done so for years, we’ve been very happy with it).

The one thing we do configure is to Exclude the FileMaker folder in Program Files and any *.fmp12 files from On-access and On-demand scans as FileMaker doesn’t appreciate intrusion by third party apps.