Unable to reload multiplayer games?

So it's now twice that me and a buddy have started a multiplayer game of Mortal Empires but are unable to load it up later. Has anyone else experienced this?

The game says it is unable to because we no longer have the DLC enabled that is required to load it up, but we never change the DLC we use so that doesn't make sense. I guess it COULD be mod related, but it doesn't say that and that doesn't really make sense since we only use graphical mods.

For reference: https://snag.gy/4epWXM.jpg

Edit: so it gives the error message and the load button is greyed out, but you can still double click the save file in the list and make it load as normal.