After I've changed my signature in Outlook and mail fonts in "Options", once I pressed OK, this is the error message:
"The end date you entered occurs before the start date"
Yes, this is very annoying! Here's the fix...
In "Outlook Options", at the left side find "Calendar". Then, at the top, can you see the "Work hours:" with the "Start time" and "End time" right below it? Now check, if the "Start time" is later than the "End time", the error message will show. Change it for example to "Start Time=8:00 AM" and the "End time=5:00 PM".
I just wonder, can Microsoft be more creative and helpful to auto-fix it!