[Can't Connect Via LAN]

I tried connecting to my brother's world, but every time I try, it either immediately kicks me, saying "invalid session", or after a few seconds of being on the world, it says "a fatal error occurred" and I can't find anything online that might help.

[Won't install mods]

I found a pattern- Anything with the Starmine mod has a problem

 

[Won't install mods]

3 hours ago, JaariAtmc said:

Seems like you are trying to download a very specific modpack of which the download link is dead atm.

But the thing is, this happens with every modpack I try

[Won't install mods]

I've been trying to download modpacks, but no matter what modpack I try to download, I get a report which apparently I can't put a picture of on here because no matter how small I make it it's still considered "too big" to attack, so I'll have to describe it: it says 

Error downloading a file for the following modpack: [it gives the name of the modpack I try to install that time]

Failed to download [some crazy long link]

Please consult mod pack author

 

 

It does this no matter what modpack I try to install- I've tried restarting my computer, and even reinstalling the launcher. It worked just fine yesterday, but today it refuses to work. Help.

Finally- here's the picture