Do you have any auto enter field options specified for this field?
What system settings have you specified for dates on your computer?
If you create a brand new database file, define a field of type date and then repeat this formatting and test with it, do you get the same results?
Where do I check about auto enter?
System formats are:
Wednesday, Jan 5, 11
January 5, 2011
Jan 5, 2011
Wed, Jan 5, 11
If I type in the date, it formats correctly and there are no issues.
If I create a new database, specify field type as Date and use the drop down calendar, I get the same exact error. If I type in the date, it is fine.
I was looking for a system setting that might specify the space as a default date delimitter.
Auto enter options can be checked by double clicking a field's definition in Manage | Database | Fields, but don't bother with that. If that were the issue, your test with a brand new file rules out that possibility (as well as the possibility that this is due to a corrupted file or layout).
I'm thinking that something odd has happened with your Install of FileMaker Pro. You might try uninstalling and reinstalling FileMaker to see if that makes a difference.