Simple Invoices 500 Internal Server Error

Simple Invoices is a free, open source, web based invoicing system that you can install on your server, desktop, or at a service provider. I installed Simple Invoices on a webhost company I rather not mention. The application was working fine, until they tweak their PHP settings several months back. As a result, the PDF export in Simple Invoices no longer worked. I was bummed. So, I was forced to run Simple Invoices from my home server, which was fun, but the issue was, I can’t access it outside of the house.

So, I decided to install Simple Invoices on my new account at Linode. Now, the funny thing was, the application won’t even come up. Not even a login page. So, I searched online for a possible solution to my dilemma. Some suggested to increase the php memory settings to 128M, but that didn’t work out for me. At one time, I thought I had a missing pdo_mysql module, but that wasn’t the case. Then, I stumbled into something that led me to the ultimate discovery.

Simple Invoices has this configuration file called config.ini located inside the config folder. One thing this application doesn’t like are extra characters inside the config file. I happen to like funky passwords with interesting characters like +-)!@#. My MySQL password happens to have a close parenthesis in it. Essentially, this extra character caused the entire application to not start. So, I change my password, and sure enough, the application worked.

So, if you ever get a 500 internal server error with the Simple Invoices application, make sure you don’t have any of those extra characters inside your config.ini file. I wasted two hours trying to fix this issue, only to be surprised by such an idiotic requirement. That means I can’t use difficult passwords for this application. I think this is either a design issue or a funny requirement of the Zend Framework, which by the way, Simple Invoices is written on. It was somewhat funny, but I wasn’t amused.