You’re staring at a blank white screen. Or maybe a scary orange box that says “There has been a critical error on this website.” Your store is down. Customers can’t buy. The phone is quiet. And you have no idea what caused it.
If you’re a shop owner, not a developer, those moments feel like watching your store burn from the sidewalk. You want to fix it fast, but you’re terrified of making things worse. The good news? Most PHP errors are like a check engine light – they come with clues. And with the right tools, you can often find and fix the problem yourself, without touching a single line of code.
Let’s walk through exactly how to use a PHP error checker – a simple tool that tells you what’s broken – and then how to fix the most common issues without breaking your store.
What Is a PHP Error (and Why Should You Care)?
PHP is the programming language that powers most of the websites you run – WordPress, WooCommerce, OpenCart, and many others. When something goes wrong in that code (like a plugin that’s out of date, a theme that’s incompatible, or a server setting that changed), PHP throws an error. That error can show up as a blank page, a message about a “fatal error,” or even just a slow, glitchy site.
Ignore it, and the problems pile up. Customers can’t check out. Search engines stop indexing your pages. Your sales drop. And if the error is serious enough, you could lose data. That’s why having a simple PHP error checker – a way to see exactly what the error says – is the first step to a fix.
How to Turn On PHP Error Reporting (Without Touching Code)
Most websites hide error messages by default, so visitors don’t see them. But you need to see them to know what’s wrong. On WordPress, the easiest way is to use a free plugin.
Step 1: Install a PHP error checker plugin
Go to your WordPress dashboard → Plugins → Add New. Search for “Error Log Viewer” or “PHP Error Monitor.” Install and activate one that shows recent error logs in a simple list. One great option is “Error Log Viewer” by BestWebSoft – it reads your server’s error log and displays it in your admin panel. No coding needed.
If you prefer not to use a plugin, you can ask your hosting support to enable error logging for you. Most hosts (like SiteGround, Bluehost, or Kinsta) have a toggle in their control panel under “PHP Settings” or “Error Handling.” Look for “Display PHP Errors” and turn it on temporarily – then turn it off when you’re done.
For OpenCart: Log into your admin panel → System → Settings → Edit your store → Server tab. Under “Error Log,” set “Display Errors” to Yes. Then go to “Error Log” in the same menu to see recent errors.
For other platforms with no fixed UI (like a custom shop): Your hosting control panel (cPanel, Plesk, or your host’s dashboard) almost always has an “Error Log” section. Look for “Errors” or “Logs” and download the latest error log file. Open it in a text editor – you’ll see time stamps and error descriptions that look technical, but the key part is the line that says something like “PHP Fatal error: Uncaught Error: Call to undefined function…” That’s your clue.
Once you see the actual error message, you can move to the fix.
The Three Most Common PHP Errors (and How to Fix Them)
You don’t need to understand PHP to fix these. You just need to know what the error is pointing at, and then take one of these three actions.
1. “Memory exhausted” or “Allowed memory size exhausted”
This is the most common error. Your website is trying to use more memory than your server gives it. It happens when you install a heavy plugin, upload a huge image, or run too many things at once.
Fix: Increase your PHP memory limit. On WordPress, you can often do this without touching code. Install a free plugin called “WP Memory Optimizer” or “WP Memory Limit” – it adds a setting in your admin panel. Or, log into your hosting control panel and find the “PHP Configuration” or “PHP Settings” section. Look for “memory_limit” and change it to 256M or 512M. Save and test your site.
If you can’t find that setting, contact your host and ask them to increase the PHP memory limit to at least 256MB. Most will do it in a few minutes.
2. “Call to undefined function” or “Class not found”
This usually means a plugin or theme updated and a piece of code it relied on disappeared. A common example: You updated WooCommerce, but a shipping plugin hasn’t been updated and no longer works.
Fix: The error message will include the name of the function or class – for example, “Call to undefined function wc_get_product()”. That tells you it’s related to WooCommerce. Go to your WordPress admin → Plugins → look at the plugin that likely handles shipping, payment, or custom features. Deactivate it (click Deactivate under its name). Does the error go away? If yes, you’ve found the culprit. Then either update that plugin, find a replacement, or contact the plugin author for a fix.
3. “Parse error” or “syntax error”
This one feels scary, but it’s almost always caused by a corrupt or incomplete file – often when you edited a theme’s function file manually, or when a plugin update failed.
Fix: If you were editing a file (like functions.php in your child theme), revert to the last working version. You can do this from your WordPress admin: Appearance → Theme File Editor. Open the file you changed and undo your edits. If you don’t remember, reinstall the theme (Appearance → Themes → click on your theme → Delete, then reinstall it – your settings stay, but the code resets).
If you didn’t edit anything, the error might be from a corrupt plugin update. Go to Plugins → find the plugin that was updated around the time the error started. Deactivate it, then delete and reinstall it. That often fixes the file corruption.
Using a PHP Error Checker Plugin to See Errors in Real Time
The plugins I mentioned earlier – like “Error Log Viewer” – are your best friend for ongoing maintenance. Once you’ve fixed the immediate problem, install one of these tools and leave it active. It will show you a list of recent errors in your WordPress dashboard. You can clear the log after a fix and see if new errors appear. This turns you into your own early warning system.
How to use it: After installation, go to the new menu item (often called “Error Log Viewer” or “Debug Log”). You’ll see a table with date, time, and error message. If you see a stack of repeats of the same error, that plugin/theme is the problem. If the log is empty after a few days, your site is running clean.
What Happens If You Ignore These Errors?
I’ve seen store owners lose weeks of sales because they ignored a small error that slowly got worse. A memory exhaustion error can cause your site to crash during a flash sale. A “call to undefined function” can prevent your checkout page from loading – and customers abandon carts. Worse, some errors silently corrupt your database, requiring a restoration from backup.
Use a PHP error checker regularly – at least once a month – and fix any errors you see, even if the site seems fine. Think of it like changing the oil in your car: a little routine attention saves you from a blown engine.
Put It Into Action Today
Here’s your short checklist:
- Install an error log viewer plugin (or enable error logging in your host).
- Look at the error messages – the key words (memory, function, parse) tell you what to fix.
- For memory errors: increase memory limit via host or plugin.
- For function/class errors: deactivate the plugin mentioned in the error.
- For parse errors: revert recent file changes or reinstall the theme/plugin.
If you follow the steps above and your store is still broken – or if you’d rather not dig around in settings yourself – that’s exactly when DevCev Digital can help. We step in, find the root cause, and fix it without you ever needing to look at a log file.