Forum Permission issues after upgrading

[محروم.كوم]

I upgraded from 4.1.x to 4.2.0 patch 2 and after overwriting my old forum files with the upgrades versions I instantly got internal error 500. Baffled by this I contacted my host and they told me the error logs stated something regarding the permission of multiple files where group was writable 755 instead of 775. After changing a bunch of the files to 775 I got the forum partially working however there are some features that just don't work such as mark forums read. Is there any reason the package had all incorrect permissions on pretty much every file and directory or am I missing something? I did nothing different when upgrading as I have done for the past 4 years. __DEFINE_LIKE_SHARE__