No New Packs Will Launch

[reikozunaken]

I've been having a severe issue with FTB packs ever since the launcher updated. Every single new pack I download gives me the dreaded mc = class net.minecraft.client.Minecraft error and nothing, even the helpdesk and basic troubleshooting steps, makes a difference. The thing is, my old install of FTB Ultimate launches fine, so I am perfectly capable of launching FTB minecraft.

Get this though, I tried copying my working FTB Ultimate minecraft 'bin' folder into other 1.4.7 pack installs and they worked! This leads me to believe that the minecraft client downloads coming from FTB servers are somehow corrupt. This problem exists on the 1.5.2 packs as well.

Being that I don't see an explosion of mc = class posts on the forums, I am willing to bet that this problem doesn't exist for most people. Either way, I'd appreciate if someone could look into this issue, as it would be nice to be able to play new FTB packs without having to use workarounds first.

 

[Ashzification]

There's an article about this on the help desk KB
http://desk.feed-the-beast.com/inde...mc--class-netminecraftclientminecraft-problem

Force update seems to work for most people.

 

[reikozunaken]

I have tried this and the basic troubleshooting multiple times with multiple packs. I have completely removed FTB and started fresh. Since I can make it work after replacing the minecraft base files with other, working files, I feel that the resources downloaded from the launcher are corrupted. Why they are not corrupted for others, I do not know.

Also, I've tried launching from two different computers, independently downloaded.

 

[Ashzification]

I have tried this and the basic troubleshooting multiple times with multiple packs. I have completely removed FTB and started fresh. Since I can make it work after replacing the minecraft base files with other, working files, I feel that the resources downloaded from the launcher are corrupted. Why they are not corrupted for others, I do not know.

Also, I've tried launching from two different computers, independently downloaded.

I did not say to try that, since you already indicated that you have tried it.
I know that there is no solution to this problem. I also know that every option within that linked article has worked for at least 20 people each. (I cannot say any more because people stop responding once their problem is fixed).
The force update option seems to work for the majority of users.

 

[reikozunaken]

The force update option seems to work for the majority of users.

This is true, though it unfortunately does not help in this case. I am hoping to get a discussion going for those who continue to have the issue after trying the steps in that article. Either way, thanks for your input.

 

[reikozunaken]

Well, it looks like someone did something. Last night, the download would fail when it got to the minecraft resources every time. When it started working again later, everything started launching fine after a force update. I can't say if it was coincidence or a known undercover bug, but it looks like we're in business again!