WSOD after installing Pressflow 6 I installed Pressflow on my Drupal 6 website by replacing core files. I only kept .htaccess, robots.txt and sites folder.

After that I got a lot of PHP errors, even after I change php.ini's error reporting.

So I checked Apache logs.

I had APC running on my site already and I noticed the following error happening frequently:

[apc-warning] Unable to allocate memory for pool.

It disappeared after I change APC memory to 16MB (it was 30MB) and restart Apache.

Although I can now load a few pages, I'm getting a white screen when trying to load home page and some other pages. Also, some regions of the page aren't showing up properly.

I tried clearing cache too.

Is there anything I'm missing?
My first step here would be try again. If you still get issues and there is nothing in the logs try increasing the memory limit.

Also there are some pressflow changes in htaccess, replace that roo.