MEX has a few built in diagnostics tools that can be used to figure out why your MEX isn't working as expected, and sometimes automatically fix errors. They can be accessed from the Control Files > Performance Diagnostics, and primarily includes the image optimiser, profiler, and **Diagnostics Tool.
Accessing the Diagnostics Tool
When first loading the Performance Diagnostics page, the diagnostics tool will be hidden. You can access it by pressing alt + s, which will make the Diagnostics Tool button appear, and then clicking the button to open the tool.
Using the Diagnostics Tool
Once the Diagnostics Tool is open, it will show you a list of all the errors it has detected on your MEX site caused by bad data. You can see what the tool is looking for, and what effects it causes on the end user in the left panel, and all the affected records in the right panel.
If the tool has detected any issues, you can select the issue and press Fix All to automatically update all of the problematic records it has detected. Once it has finished running, the issue will disappear from the panel on the right as it has been resolved.
The diagnostics tool is constantly being updated with new scripts to find and eliminate bad data across MEX. If you are experiencing any issues, it is a good place to check first, as we may already have the solution ready for you!