What is iTunes Error Code: -9810

Recently my iTunes Match refuses to complete any adding or updating. It seems to run forever and stops an 'Error Code' -9810. It tells me to try again later, but this has been going on for weeks.

I have a feeling that this might be due to iTunes Match "choking"on one particular song or album that I have recently added but

I'm not sure what to do about it.

I have run through the whole bag of tricks to no avail, except for sorting by 'Date Modified' and pulling the suspect albums out of the iTunes Media file (which I am going to try now.)