From [4] I learn:

"I have a Hostgator shared hosting with PHP 5.5."

PHP 5.5 is EOL since mid of 2017. Can't you switch to newer version such as 7.2?

Matomo itself does not even display the required version according to [1]. Their FAQ talks about 5.3 - which is horribly ancient too.

[1] https://matomo.org/docs/installation/

Hi,

I have to agree that one should be using PHP 7.2. It also gives a nice performance boost to Matomo. The required PHP version for Matomo is shown in [1] (5.5.9 or greater) Can you please send me a link to the FAQ page mentioning 5.3 (e.g. to [email protected]) so they can be updated?

[1] https://matomo.org/docs/requirements/

My mistake, I was skimming the docs only but overlooked the specially linked requirements. I would go further though and remove outdated PHP versions from that page and only recommend maintained versions.

Additionally, the error described by OP looks like autoloading is broken.

Thanks! I find how to upgrade to 7.2 [1]. Will try it again!

[1] https://support.hostgator.com/articles/php-configuration-plu...

This project used to be called Piwik. 10 years later and they still only support MySQL; a lot of people really wanted at least Postgres support.

I've been playing with Matomo recently and opted to use a premade container [1] for it and that was working pretty well.

[1] https://github.com/crazy-max/docker-matomo