Is it impossible to install mods with hostgator?

[Nylese]

I tried installing an invite-only mod. When it wouldn't install, I googled the problem and did the main piece of advice I saw which is make a directory called "temp" in the "Package" directory, and chmod it to 777. Still didn't work. I got the 500 - Internal Service Error instead. Hostgator fixed it for me and said the mod would install if I tried it again but it didn't. Done this three times now. Help please! 

If I have to change hosts, please recommend some that won't cause me this issue! I need this mod. Thanks.

[Kindred]

Well, what was the actual error that you got during the installation attempt?

Try 755 instead of 777