You may see bad stats on items, like 'Unrecognized Property' instead of '+3 to damage', this is because Blizzard has broken some of the files backing D2R modding. Please extract this to a new folder, it cannot read the clipboard.d2x stash from your existing D2 Gomule folder. It might refuse to startup because you're trying to re-use your existing D2 GoMule folder.

You may run into some trouble with this release, like: View (and create Flavie reports) but not modify D2R shared stashes (.d2i format) - the file format is still not decoded.

There's also various convertors around the internet that you might have success with, but just like me they don't understand the entire save file structure and may not create the exact structure that D2R expects. If you need to convert legacy D2 items to D2R format, you'll need to create a new D2 character, load it up with the items you want to convert, save it, copy it to your D2R folder, open it in the D2R game. GoMule only has functionality to allow items to be moved around, it doesn't edit any item fields aside from their location. Some notes - this does not allow you to convert characters or items between legacy D2 and D2 resurrected.

Diablo 2 resurrected item spacing