How to debug random errors

[mel47]

Hi,

I have randomly some errors in my log. I have no clue where to start to find the cause. It's either on "/" page or some inexisting pages. 
Is it an incompatible module or something with a fieldtypetext?
I upgraded all modules and could wait to see if it disappears but except that I don't know where to search. If someone is willing to explain how they debug this kind of errors, I will appreciate so much!
Mel
 

Fatal Error: Uncaught Error: Class 'FieldtypeText' not found in /wire/modules/Fieldtype/FieldtypePageTitle.module:17 Stack trace:
1. /wire/core/ModulesFiles.php(324): include_once()
2. /wire/core/ModulesLoader.php(682): ModulesFiles->includeModuleFile()
3. /wire/core/Modules.php(667): ModulesLoader->includeModule()
4. /wire/core/Modules.php(574): Modules->includeModule()
5. /wire/core/Fieldtypes.php(194): Modules->getModule()
6. /wire/core/Fields.php(203): Fieldtypes->get()
7. /wire/core/WireSaveableItems.php(260): Fields->makeItem()
8. /home/xyz/domains/omn
Line 17 of /wire/modules/Fieldtype/FieldtypePageTitle.module

 

[cwsoft]

My debugging solution depends on the PW and PHP version I am one.

In your case I would first try to upgrade the PW core with the latest version from the master or dev branch. For that I upload/copy latest wire/ folder with all files and subfolders to my site as wire.new/. Than I rename wire/ to wire.old/ and wire.new/ to wire/ and reload the page. Then I login to the backend and reload the admin and modules 2-3 times. Next I would check the logs and see if that already solved the issue. https://processwire.com/docs/start/install/upgrade/

If that doesn‘t solve the issues, I would install Tracy module and dive deeper into the issues. But before I do this, I always ensure I am on latest PW core with the recommended PHP version for the core version.

Edited August 6 by cwsoft

[bernhard]

Random errors are the worst! 😉 

If you have TracyDebugger installed already you might also want to look into the folder /site/assets/logs/tracy

You might find some tracy bluescreen html files there which you could copy to your computer and open in a browser and see something like this:

You can click on each item of the trace and you'll see where the problem occurred (top arrow) and also which arguments have been sent to the method (bottom arrow).

Good luck 🤞

[mel47]

11 hours ago, bernhard said:

If you have TracyDebugger installed already you might also want to look into the folder /site/assets/logs/tracy

Thanks! Simple thing but, now, I know which module is the cause. Still have to found the solution though! 😉 

[adrian]

On 8/6/2025 at 7:58 AM, bernhard said:

If you have TracyDebugger installed already you might also want to look into the folder /site/assets/logs/tracy

You might find some tracy bluescreen html files there which you could copy to your computer and open in a browser and see something like this:

Just an FYI - the TracyExceptions panel will list all these and let you load them up much more easily.