Level Info data missing or invalid.

[JJhonJames]

Trying to open some resources & systems from Hiveworkshop, but some resources (in form of maps) just have this error happening upon loading in World Editor.

One of these maps is a common w3x extension, while the other is w3m. Does this have to do with version?

 

[Uncle]

Yes, you're missing whatever new things were used in that map.

 

[Ravager16829]

Check the map version before downloading the resources (maps) from this site.
If the map was saved in Reforged World Editor (1.32+), they can't be opened with the previous version of World Editor (up to 1.31).
Most W3M maps are made with the Reforged World Editor, iirc (probably because both Reign of Chaos and Frozen Throne are merged into one game).

You can also use this workaround to make certain maps openable with legacy WE (I can't guarantee if this trick works on all maps):

Map Adapter

Have you ever wanted to play a map but couldn't, because it was made with Reforged's World Editor? Well today is your lucky day, because now you can make those maps compatible with patch 1.31 (1.30, 1.29, and 1.28 also supported, or any patch for which you have the game files since v1.0.0)...

www.hiveworkshop.com