Mostly known PHP error messages reported

This topic demonstrates the most reported errors by forum users. Followed is a definite demonstration on how to resolve these issues.

/vqmod/vqcache/vq2-xxxxx.php

All instances beginning with vq2- is an error generated from the VQMod cache folder which cannot be reproduced within a core installation of Opencart before the installation of Opencart. This error has indication that one of the installed XML file is causing problematic issues for one or many reasons. An easy solution would be to download the VQMod Manager: viewtopic.php?f=183&t=156866&p=611059#p611059 and to either troubleshoot or disable each XML files - one at the time - and refresh the current page where you'd notice the error message - one process after another - until that error message disappears. Once disappeared, clear your vqcache from your vqmod/vqcache folder and system/cache or system/storage/cache folder (excluding the index.html file). Then, reload your site. As a final result, it would, then, be suggested to contact the developer of that specific extension that caused this error message to appear.

/system/modification or system/storage/modification

Developed for Opencart v2.x releases, the system/modification path error message means that one or many of the installed extensions located in the admin - > extensions - > extensions (OCMod):



is causing a problem. Simply uninstall one extension at the time and refresh the affected page where you see the error - one process after another - until that error message disappears. Once disappeared, it would, then, be suggested to contact the developer of that specific extension that caused this error message to appear.

MySQL server has gone away

There has been many reports on the forum regarding the: MySQL server has gone away message. Followed are detailed information provided by Daniel explaining the facts on why this issue occurs: http://forum.opencart.com/viewtopic.php ... ay#p391708

Emails

There has been countless reports regarding the: 'Error: EHLO not accepted from server!' error message preventing the emails to be successfully sent. This error message is either caused by one or many misconfigured parameters from the admin - > systems - > settings - > edit store - > mail tab. In order to fix this issue, the mail parameters entered to the form must be properly filled. If you do not know the exact configuration for your email settings, it would be suggested to contact your host to obtain those information or you can always obtain those information by the email confirmation bill your host provided since the order registration process for the specific hosting plan you have registered for.

However, if you DO have the right information and not only convinced on having those information saying: 'Yes, this is the right information and I know it' but you also DID tested the entered information as it may or may not be sending successfully depending on the Opencart page, followed provides the possibilities:

- You are not using the latest version of Opencart
- You are using an extension that may differ the ways of sending emails compared to the core files
- Invalid entries have been entered in the mail form settings
- Your host's email server may strictly support POP before SMTP Authentication which OC does not support at this time
- You are attempting to send emails from a mobile network which your provider might have authenticated
- Your mail settings for the web has been disabled by your host

After validating these 3/4 facts above, if the issue still persists and your host cannot resolved the issue, it would, then, be suggested to look for another web hosting party.

Blank pages

Detailed instructions can be found on this topic regarding blank pages troubleshooting steps: http://forum.opencart.com/viewtopic.php?f=170&t=50555

ProxyError

Most ProxyError messages originates from a developed extension / module which at least one of the controller files and / or at least one of the model files are not properly titled compared to the designated path of the store. All core files should normally be linked relatively to the structured engine in Opencart.

Take note there is nothing wrong with the ProxyError file itself. All controllers and modules that have not been reported otherwise our properly working out-of-the-box.

MySQL deprecated

Deprecated: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in /home/USER/public_html/system/library/db/mysql.php on line 7"

This message indicates the abolition of MySQL library by the Oracle Industry. mysqli or mpdo should now be used into the root config.php and admin/config.php files as followed:
or:
Note: By using mpdo, it provides multiple database connections. However, the mount of sockets are more limited than mysqli which MySQLi only provides one database connection at the time. After instantiating the above configuration instructions, if other error messages from mpdo persists on your store, it would be best to contact your host to resolved this issue.

Proxy Errors

Just so for everyone to know, there is nothing wrong with the proxy Engine class in Opencart. This error originates from improper class declaration either from the controllers or from the models. There might also be times when a class can be properly declared but improperly structured. These particular events may be encountered on virtual servers, on POSIX infrastructure and SOLARIS servers. The Opencart team have already been addressed from the bug reports section of the forum to ensure the use of the right structure regarding the declared class names either from jQuery or from PHP controllers / models files.

Example from a bad declared controller file:
Ensure to rather use:
Same methodology for the models but begin with: Model at the beginning and extends with: Model .

Also take note due to the upgrade of v2.3.0.2, the class route methodology is handled differently based on the extension path.

In addition, the way on declaring a model method from a specific controller may also be involved with the above note.

Repair Database Tables

It may happen once in a while that a database table might be broken while using any platforms on your domain. Followed are detailed examples on how to fix this issue: http://forum.opencart.com/viewtopic.php ... 48#p632253