A blank screen is almost always caused by a fatal error given by PHP. The reason the error is not shown is because on most production systems the setting display_errors is set to off. To verify if this is the case check the PHP settings on your system.
When does this happen?
- During installation of CSVI
- When opening CSVI
- During import
- During export
Where to look?
The exact error is to be found in the server error log. This must be found first before any other action can be taken. Without the error, it is almost impossible to know where to look.
Go to the Global Configuration and on the Server tab set the Error reporting to Maximum, now save the configuration. Now errors will be shown on the page where the problem is.
If you still don't see errors you there is an alternative way. Add the following code at the end of the configuration.php file:
ini_set( 'display_errors', true );
error_reporting( E_ALL );
This turns on all error reporting and set to display the errors.
The fatal error is usually one of these:
- Out of memory
The file you are trying to upload is using more memory than your system has available
- Maximum execution time exceeded
The file you are trying to import takes too long to process
- File not found
The program tried to include a file that does not exist
- Function does not exist
A function is called that does not exist, for example stripos().
A piece of code is called that does not exist
Out of memory
The out of memory has several possible solutions:
- Make the import file smaller or limit export setings
- Increase the memory limit in the template
This may not always work as not all systems allow CSVI VirtueMart to change these settings.
- Increase the memory limit in PHP settings
How to change these settings depends on the system. Some hosts do not allow changes, others use a local php.ini and others user .htaccess. Check with your hosting provider on how to change this value. The PHP value to change is memory_limit.
Maximum execution time exceeded
The maximum execution time exceeded has several possible solutions:
- Make the import file smaller or limit the export setings
- Increase the maximum execution time in the template
This may not always work as not all systems allow CSVI to change these settings.
- Increase the execution time in PHP settings
How to change these settings depends on the system. Some hosts do not allow changes, others use a local php.ini and others user .htaccess. Check with your hosting provider on how to change this value. The PHP value to change is max_execution_time.
- Do a manual installation of CSVI
File not found
Important is to find out what file is not found. This can be found in the logfile or if errors are displayed, the filename will show on screen. The file not found has several possible solutions:
- Check if the installation of CSVI went fine
- Check if the file exists or not
Function does not exist
The reason here is that an older PHP version is used. Check if your system is running PHP5.
Report the exact error as found in the server error log on the forum.