"missing descVersion attribute" connecting multiplayer [PC]

[DirectCedar]

Question for someone more knowledgeable about multiplayer mod compatibility issues than I am.

I have a long-running FS17 multiplayer game and we've never had trouble connecting and never had this particular error before.

Suddenly yesterday, one and only one of the players trying to connect, got this error above in the subject line ("missing descVersion attribute") for one specific mod that used to work fine. This prevents him from connecting to the game, and makes this mod unusable for him in single player games as well.

The EXACT SAME FILE worked yesterday, and works fine on three other computers to connect to the game. It does not generate this error on any of the other machines.

I have tried emailing the "good" mod file from two other computers to the problem one, and none of them correct the problem. The same error shows up on the problem computer even after he has replaced his copy of the mod.

Any ideas? Thanks kindly for any insight. I recognize that I am asking this about 17 but I am suspicious the solution is the same as it would be in 19.

[BulletBill]

That error comes up if the player is not running the same game version as everyone else. Especially if it won't work for him in SP either.
The descVersion range in Fs17 was 32 - 39. Get him to check he's running the up to date version of Fs17 and your problem should be sorted.