So many issues

[Bbez2000]

So I had this mod pack for a week or two and then my computer updated or something. After that, every time I went to play, I would receive a message that would say "Bad compressed data format". So I deleted the launcher and tried to reinstall it but my computer wouldn't let me without my firewall off. After that it still didn't work so I kept deleting and reinstalling the launcher. However now it seems that I have lost all the mods required to play on the server and have no idea how to get them back. Please help if you know anything about this.

[Munaus]