Error: "The entered value does not repsect the field format or type" - Unable to add comments in the "Delivery Comment" box of Order Management

When trying to add comments in the "Delivery Comment" box of the "Delivery" tab on the Order Management screen, I encounter the error message in the attached screenshots. This seems to occur when trying to add several comments.  I'm trying to shorten the comments to avoid this problem.  However, this PO has had a few reschedules thereby requiring more comments. 

Would greatly appreciate any input or insight as to why this might be occuring and what would be the proper remedy.


Thank you!