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# Why do I get this error: Call to undefined function: mcrypt_module_open()

If you receive the following error:

||| Fatal error: Call to undefined function: mcrypt_module_open()

It is likely that you do not have mcrypt with curl ssl support compiled into your PHP. You must have your host re-compile PHP with mcrypt and curl ssl support in order to store credit cards in Clientexec. It is a requirement if you plan to use a merchant gateway such as Authorize.net, etc.