GBX Mods instead of ZIP

[virtualmarc]

Hello,

I recently downloaded some mods out of the internet and used them in my own maps.
Some Mods were delivered in a .zip Archive and some as a .gbx file.

Now I started a server. The mods downloaded without any problems (I see the request in my access.log on the server).
The Mods in .zip Archives work perfectly but the .gbx files were downloaded but nothing happens.
The only one who can see the mod is me, every one other sees the standard textures.
Even when the others download the gbx File they don't see the textures, they see them first if they once opened the editor and payed for the mod, but thats not what I want.

The target is to have the maps on a dedicated gameserver where everyone can play and everyone should see the custom textures. Like I said, the .zip Files work great but the .gbx files fail at this point.
Is there any way to unpack the .gbx files and repack them as .zip files to get them working?

Regards,
Marc