Installation document for Slider Product Images to Opencart 4.x

Requirements

1. Requirements

ℹ️Info: Verify all requirements below before uploading a module, depending on which packaging method the extension uses: VQMOD or OCMOD. Supports both VQMOD and OCMOD side by side. As of OpenCart 4.x, VQMOD is no longer officially supported — all extensions are packaged as OCMOD (.ocmod.zip format).

VQMOD

Requirement	Notes
Installed and activated VQMOD	Requires version 2.5.1 or higher. Applies only to OpenCart 4.0.x.
Writable folder `vqmod/xml` and `vqmod/vqcache`	Set CHMOD 755 or 775 (avoid 777 unless necessary)
Executable file `vqmod.php`	Ensure CHMOD 755 or higher
Error checking	Review `vqmod/logs/vqmod.log` if installation fails
`vQMOD` How to Install vQmod for OpenCart 4.x

OCMOD

Requirement	Notes
Administrator permission for OCMOD	Required to install and manage extensions
Writable folder `system/storage/modification`	CHMOD 755/775, needed so the system can store the compiled patch
FTP configuration (if using the Installer via FTP)	Required when uploading extensions through the Installer feature
PHP version	PHP 7.4–8.0 (OC 3.x) · PHP 8.0–8.1 (OC 4.x)
Error checking	Go to Extensions → Modifications → Refresh to see OCMOD compilation errors

⚠️Warning: Always back up the database and the entire source code before installing any extension. Double-check all the requirements above before moving on to the upload step.

1. Upload

1. Upload Module

The process of uploading the extension file to the system through the Admin Panel.

Download the extension
Get the module file from a trusted source (OpenCart.com, OpenCartPlus.com, or the official vendor). The file is usually .zip or .ocmod.zip / vqmod xml.
Log in to the Admin Panel
Go to http://yourdomain.com/admin using an account with administrator rights.
Go to Extensions → Installer → Upload:
The system requires a modification file with the extension '.ocmod.zip'. Click the button and select your file. The system will automatically extract and validate the file structure.

Image 1.1: Upload button in OpenCart Admin

Note: If the package is provided as a standard '.zip', first extract it and then choose the '.ocmod.zip' file inside for installation.
Confirm
The system shows a success message if the file is valid. If it shows an error, re-check the folder write permissions from Step 1.

2. Add permission

2. User Group Permissions

Login to your OpenCart admin panel and go to System → Users → User Group.

Click Edit on your user group name. (Default user group name is Administrator, see Image 2 below).

Image 2: Admin User Group

Next, check Access Permission and Modify Permission (see Image 2.1).

Image 2.1: Add Permission

extension/module/redirect_manager_pro

3. Installation

Activate the extension after the file has been uploaded successfully.

Install from the Installer for Opencart 4.x
Go to Extensions → Installer, find the extension name you just uploaded, and click the Install icon (+).

Figure: The name of the extension you just uploaded and the Install (+) icon.
Choose the extension type
Go to Extensions → Extensions select the corresponding extension type in the dropdown (Modules, Payments, Shipping, Themes...), find the name of the extension you just uploaded in the list → click the Install icon (+).

Figure: Choose the extension type

Note: To correctly select the extension type when installing an extension, check the file extension_name.php inside the upload folder of the downloaded .zip or .ocmod.zip. The directory where this file is located (for example: payments, module, other, etc.) indicates the type you should choose in Choose the extension type.

Figure: click the Install icon (+)
Activate the extension
Find the extension name in the list → click the Edit (pencil) to enable and configure it.

Figure: click the Edit (pencil) to enable and configure
Activate the License Key
Enter the license key provided on the download page or in the purchase confirmation email.

Figure: Activate the License Key

4. Configuration

Set the operating parameters for the extension.

Go to Extensions → Extensions → Choose the extension type → Modules → OpencartPLus.com Slider Product Images → click the Edit (pencil).

Image 4.1: Configure Slider Product Images

Add motion, speed, and professionalism to your OpenCart product thumbnails. Upgrade your user experience today with Slider Product Images

⚠️Warning: Do not share API keys or payment gateway credentials publicly. Store this information somewhere secure.

5. Clear Cache & Use

Clear the cache to make sure your changes take effect on the front end.

Go to Admin Panel → Dashboard → Developer Settings, then click the button to clear old cached data.

Figure: Refresh developer settings

Figure: Refresh developer options
Check Extensions → Modifications → Clear → Refresh to ensure that OCMOD modifications are recompiled correctly.

Figure: Refresh modifications clear

Figure: Refresh modifications
If the extension uses VQMOD, also clear the cache in the folder vqmod/vqcache/ located in your OpenCart root. Inside the vqcache folder, you will see multiple files named like vq2-xxxx.php. Delete all these files (do not delete the folder itself).

Figure: Clear the cache in the vqmod/vqcache/ directory

6. Final Step & Enjoy new extension

6. Final Step – Enjoy Extension

The last step to confirm the extension is working correctly.

Go to Extensions → Extensions → Choose the extension type → Modules → OpencartPLus.com Slider Product Images → Edit and adjust any final settings if needed.

Accessing the product list within a category on the online store interface helps ensure that the module is displayed and operates correctly in the live environment.

✔ Journal 3.x theme

Image 6.1: Slider Product Images Journal 3.x theme

✔ Default theme

Image 6.2: Slider Product Images

If everything displays correctly with no errors in the console/logs, the installation is complete.

7. Common Troubleshooting

Extension doesn't appear after Install

Recheck the cache (Step 5) and make sure the module is set to Edit → Status: Enabled. For OCMOD, also check Extensions → Modifications → Refresh.

VQMOD error: "File could not be found"

Usually caused by an incorrect path in the VQMOD XML file, or the vqmod/vqcache folder not being writable. Check the log at vqmod/logs/vqmod.log.

White screen after installing OCMOD

Go to Extensions → Modifications, click Clear then Refresh to remove the faulty modification cache, then try again. If the error persists, manually remove the extension's file from system/storage/modification.

Layout breaks after installing

The most common cause is the extension containing CSS/JS written for the wrong Bootstrap version. Cross-check the classes it uses against the Bootstrap version your OpenCart is running (OC 3.x uses Bootstrap 4, OC 4.x uses Bootstrap 5).