We have developed and tested personal feeds to be able to accept any item from RSS Ground private feeds and from most of the other public feeds. However, public feeds can be invalid, have bugs and errors in the source code, or miss important parameters. Unfortunately, we don't have control over it and can't process items from such feeds.
In case we can't add an item to your personal feed, you will see an error message:
Please, contact our support team and provide the content feed you have problems with, so we could find out what the problem is and issue a possible fix.
Another way around - add this item manually. Create a new item in your personal feed and copy/paste content from the needed item.