Cannot submit listings to eBay - Input Data is Invalid

[doecreations]

This is a new problem for me.  I Use Wonder Lister as a third party listing service.  Beginning a couple of days ago, all of the listings I submitted to eBay, did not go through, because of "Error: Input Data is Invalid".  Most of these are items I have submitted in the past, that went through with no problem.  I have gone back and checked the listings, and cannot find what data is missing or might be invalid.  And why would this error appear on ALL of my listings?  Wonder Lister has not been able to help me yet with this issue, as they seem to think it originates with eBay.  Maybe so, but how can I fix it?