RVsitebuilder 6 for DirectAdmin requires PHP 5.6 only. But you can set PHP56 custombuild when your DirectAdmin server is running PHP7.
Do this before running install RVsitebuilder 6.4 on your DirectAdmin server.
Check if your DirectAdmin server has PHP56 installed as additional PHP version by running command:
A. The following result is showing it's installed. You can run install RVsitebuilder 6.4 on your DirectAdmin server immediately without going through B.
PHP 5.6.40 (cli) (built: May 5 2021 15:18:50)
B. If your server don't have PHP56 additionnal version, the result returns as below.
-bash: /usr/local/php56/bin/php: No such file or directory
Please rebuild custom PHP with the following command.
cd /usr/local/directadmin/custombuild ./build set php2_release 5.6 ./build update ./build php n ./build rewrite_confs
Then you can install RVsitebuilder 6.4 on your DirectAdmin server.