I went to contribute a boxset using the instructions found here:
https://www.mymovies.dk/how-to/guides/collection-management/creating-box-sets.aspxI struck an error during the contribution when following this section of the instructions:
"Select the title profile of the box set container and then click ‘Title’ and select ‘Contribute Title Data and Cover’. From the pop up window select ‘As Box Set’ to contribute the box set to the web service."
The error indicated that the covers matched the covers on the server which is true, they did, as I was using an existing title as the container/parent. There were no further messages to indicate any of the contribution attempt had been successful and checking the 'WebService>View History' listing for the boxset container title showed no contribution against my name so it had seemingly rejected my entire boxset contribution attempt. The boxset parent title already existed and there was no need for me to make further alterations to the covers for that title but I did need to contribute the covers for the child titles I had just created and linked. To work around the problem I removed 1 row of pixels from the top of the front cover which is imperceptible due to the high resolution of the image but the server would no longer see it as an exact match to what it already had. Thus when I tried contributing the boxset again, this time it gave the accepted message (and reminded me that it would require approval as a boxset contribution which I understand and expected). I can also see my contribution now listed in the 'WebService>View History' listing for the parent boxset which is cool so all good.
The instructions on this site indicate using an existing title if it is effectively the boxset container title but makes no mention about needing to update the covers for that title before submitting your completed boxset contribution in order to avoid error/failure. I recommend having the webservice register that if the incoming contribution is a boxset then ignore if the covers for the parent title are an exact match to what is on the werbservice already, as the child titles will have new covers that need uploading as part of the contribution.