Server Requirements

Supported web servers: 
Apache, LiteSpeed, Nginx, Lighttpd, IIS, WebServerX, uWSGI

php5.6x – tested up to – php7.1x max!
cURL support = enabled

allow_url_fopen = on
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Recommended settings for your ->  php.ini file.
error_reporting = E_ALL|E_NOTICE|E_STRICT
display_errors = Off
log_errors = On
memory_limit = 256M
max_input_vars = 20000
max_execution_time = 300
max_input_time = 600
upload_max_filesize = 100M

And for using maps you may need to go ahead and add these to the php.ini file as well.

extension=pdo.so
extension=pdo_mysql.so
extension=pdo_sqlite.so
extension=sqlite.so
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MYSQL 5.6  –  5.7 max
You MUST disable strict mode! – If you attempt to install and get an activation error then this may be the reason!
If you are on a vps or dedicated server then you will typically need to do this in 2 places = phpmyadmin as root under variables link (google it) and also in the etc/my.cnf  and then reboot mysql and it should be good to go.
(if you’re on a managed hosting then they typically already have “Stric” turned off as we do on our servers.)
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Next you will possibly need to open up TCP ports if RETS connection fails and or you have any of these “Numbers” within your RETS connection url.
TCP –  6103  |  6160  |  8080
* example url: http://rets.torontomls.net:6103/rets-treb3pv/server/login
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