So I just upgraded my test board and it seems to be fine for now except one thing.

I am logged in fine. However, if I try to login as a regular member(under a test account), it redirects me back to my actual main board instead(which is on 3.X still). Why is this and how exactly do I fix this?

In fact none of the links work when you click on forum or threads...they all redirect back to the 3.x board saying there was an error.

I had this; in the ACP you need to turn friendly URL's on and download the htaccess file, and reupload it to your 4.0 root folder. (Example: If 4.0 install is located on https://www.domain.tld/ips4/ then it'd be in that folder). Also check your conf_global.php file and if there is a $INFO['use_friendly_urls'], set it to '1'; 

If you don't want Friendly URLs turn it off in the ACP and if there is a $INFO['use_friendly_urls'] set it to '0'; 

I hope that helps. As I said I had the same thing, and the above fixed it.

Edited April 11, 201510 yr by Tripp_UK

I had this; in the ACP you need to turn friendly URL's on and download the htaccess file, and reupload it to your 4.0 root folder. (Example: If 4.0 install is located on https://www.domain.tld/ips4/ then it'd be in that folder). Also check your conf_global.php file and if there is a $INFO['use_friendly_urls'], set it to '1';

If you don't want Friendly URLs turn it off in the ACP and if there is a $INFO['use_friendly_urls'] set it to '0';

I hope that helps. As I said I had the same thing, and the above fixed it.

​It did thank you!

Thanks, the same for me, working great now.

Awesome stuff. I'm glad it helped.