Internal server error in some pages and cookie problem

[lfpm]

Hello ,

2 days ago, I have upgraded my 3.8.1 forum to 4.2.

However, i am facing some problems here and there, hopefully you can help with.

Problem 1:

When i enable the BLOG or some other plugins, some profiles start giving me a blank page on firefox and internal server error on chrome.

Could it be a files permission problem ?

It is not a DB error since nothing is being logged and no email is sent to me.

Now, the blog and other plugins are disabled, so i can enter all member profiles fine.

Any ideas on how to solve this ?

Problem 2:

I think this is a cookie problem but i cant figure it out.

Some users, not all of them cant login.

When they login, the login confirmation screen appears telling them that their login was successful. After this, the page redirects and they are logged out.

My cookie path is " / " and cookie domain is blank.

The link of the forum is : www.oroom.org

Thanks