Morning @memology 

I don't think there's much I can add to what I've written previously and it's probably best to let Kat deal with things now; hopefully her response will provide the answers.

The one thing I would say, however, is that I suspect you are one of only a few users who have such an extensive WatchList and that's very probably the reason this issue has arisen.

Without access to the actual code to confirm it I can only surmise but I would guess that the counter for the number of items on a WatchList is defined on the database as being 3 digits long. That number is displayed as 'Status: All (number)' at the top of a WatchList and the drop-down arrow next to it allows for a further choice between Active and Ended items on the list.

A 3 digit field would explain why you are limited to 999 items in the WatchList. Attempting to add another item, as you have established, does nothing and I strongly suspect that the reason it does nothing is that the process has not been coded for exception handling - it was simply never expected that anyone would have more than 999 items in a single WatchList so why code for something that will probably never happen? Yes, a competent programmer would, but this is eBay...

This does need to be confirmed but I suspect this explains the bother you've been having: eBay's system is designed with a maximum number which can be added to a WatchList. You're trying to exceed that limit but there is nothing in the code which alerts you to that fact.

I'll leave it to Kat from here on in.