1.7.5.0 Server error on certain backoffice pages

[JohnDom]

Hi, I have tried to install the 1.7.5 from scratch and even upgrade to it from several 1.7.4.2 fresh installs.
So, only demo data.

I keep facing the same issue after the install, or after the upgrade, where whenever I try to load backoffice pages that make requests to the database, I get the 500 internal server error.
So I can log in and visualise the dashboard fine, but if I try to go on to the products page or performance page, for example, I get the 500 server error.

I turned the debug mode on through FTP but I can't see anything that can help me work out the problem.

In debug mode I can access the troubled pages without issues.
When I investigate, there are some minor warning messages, screenshots below:

[JohnDom]

I have found the solution to this one myself.

I wasn't exactly sure what was the issue when I first posted this. It's to do with the caching in general and in my case with the hosting through Cloudways which adds some extra caching that can make this problem extremely hard to solve.

I solved mine doing the following:

• cleared all files in the var/cache/ folder
• I restarted Apache
• I restarted Memcached
• I restarted Nginix
• I restarted MySQL
• Finally I restarted the whole server as well. 

Hope this helps someone else.