@jgallias based on the question you asked, if you have not done so yet, I would suggest that you first try re-installing both the Gantry 4 Framework and Template before doing anything else.
You can find the latest versions here
I would also suggest that you consider starting to migrate your existing Gantry 4 website(s) to Gantry 5 as Gantry 4 will most likely be phased out in a couple of years after the official release of Joomla! 4.
@fdallera in the G5 chat room you wrote:
I would like to upgrade my Gantry 4 default template from 4.1.4 to 4.1.18, the last one but if i try to load in theme page it gave me that there is another version
There are 2 files you need to install, the theme and the framework. Have you tried installing both of them?
This is the link for the Framework:
This is the link for the Gantry 4 template: