Errors while checking out your orders can be a nightmare for any online store owner. If you use Open Cart, a popular open source e-commerce platform, you may have experienced this problem before. These errors can damage your reputation and revenue. In this article, we will show you how to solve OpenCart error while checkout and make sure it never happens again.

• Internal Server Error
• SyntaxError: JSON.parse: unexpected character at line 1 column 1 of the JSON data
• Fatal error: Uncaught Exception: Error: Could not load model webservices/fcm!

These errors can prevent you from completing your transactions and frustrate your customers. In this article, we will show you some possible causes and solutions for these common errors.

Internal Server Error

An internal server error means that something went wrong on the server side, but the server could not identify the exact problem. This error usually appears as a popup message when you click “Continue” at the first step of the checkout page.

There are several possible reasons for this error, such as:

• Incorrect file permissions
• Corrupted .htaccess file
• PHP memory limit exceeded
• PHP syntax errors

To troubleshoot this error, you can try the following steps:

• Check the error log file in your Open Cart admin panel or your server control panel. This file may contain more details about the error and its source.
• Enable error reporting in your index.php file by adding the following code at the top of the file:

ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

This will show you the error instead of the popup message.

• Check the file permissions of your Open Cart files and folders. They should be set to 755 for folders and 644 for files. You can change them using an FTP client or a file manager in your server control panel.
• Rename or delete your .htaccess file in your Open Cart root folder. This file may contain some rules that are causing conflicts or errors on your server. If this solves the problem, you can create a new .htaccess file with the default Open Cart rules.
• Increase your PHP memory limit in your php.ini file or your server control panel. The default memory limit for Open Cart is 64M, but you may need more depending on your extensions and modifications. You can try increasing it to 128M or 256M and see if that helps.
• Check your PHP code for any syntax errors, especially if you have modified or added any files recently. You can use a PHP validator tool or a code editor to check for any missing brackets, semicolons, quotes, etc.

SyntaxError: JSON.parse: unexpected character at line 1 column 1 of the JSON data

This error means that the server returned an invalid JSON response that could not be parsed by the browser. This error usually appears as a popup message when you click “Continue” at the first step of the checkout page.

There are several possible reasons for this error, such as:

• A PHP warning or notice that is printed before the JSON output
• A missing or extra comma in the JSON output
• A malformed JSON output due to a PHP syntax error

To troubleshoot this error, you can try the following steps:

• Check the error log file in your Open Cart admin panel or your server control panel. This file may contain more details about the error and its source.
• Enable error reporting in your index.php file by adding the following code at the top of the file:

ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

This will show you the error instead of the popup message.

• Check the JSON output of your checkout page by opening it in a new tab or window. You can do this by copying and pasting the URL from the console error message, such as:

http://localhost/index.php?route=checkout/checkout/country&country_id=123

You should see a valid JSON output like this:

{"success":"Country set","zone":[{"zone_id":"1953","country_id":"123","name":"Alabama","code":"AL","status":"1"},{"zone_id":"1954","country_id":"123","name":"Alaska","code":"AK","status":"1"}, ... ]}

If you see anything else before or after the JSON output, such as a PHP warning or notice, a HTML tag, or a blank space, then you need to fix it.

• Check your PHP code for any syntax errors, especially if you have modified or added any files recently. You can use a PHP validator tool or a code editor to check for any missing brackets, semicolons, quotes, etc.
• Check your JSON output for any syntax errors, such as a missing or extra comma. You can use a JSON validator tool or a code editor to check for any invalid characters or formats.

Fatal error: Uncaught Exception: Error: Could not load model webservices/fcm!

This error means that Open Cart could not load a model file that is required for some functionality. This error usually appears as a popup message after placing an order.

There are several possible reasons for this error, such as:

• The model file does not exist or is corrupted
• The model file has incorrect permissions or ownership
• The model file has a PHP syntax error

To troubleshoot this error, you can try the following steps:

• Check if the model file exists and is readable in your Open Cart folder structure. The model file should be located in:

catalog/model/webservices/fcm.php

If it does not exist or is corrupted, you need to restore it from a backup or download it from the original source.

• Check the file permissions and ownership of the model file. They should be set to 644 and belong to your web server user (usually www-data). You can change them using an FTP client or a file manager in your server control panel.
• Check your PHP code for any syntax errors, especially if you have modified or added any files recently. You can use a PHP validator tool or a code editor to check for any missing brackets, semicolons, quotes, etc.

I hope this article helps you solve open cart error while checkout. If you have any questions or feedback, please leave a comment below.