I have a problem with a drupal theme. I edit an already existing theme css and installed it in my server. It's responsive regardless of the changes I made but when I install it in another server is no longer responsive. Both server has Drupal 7.40 installed, yet I can't find why the theme isn't responsive in the other server Thanks
No matter on what server you are running your site if servers are set well output should be identical. Meaning HMTML, CSS JS files, images should be the same. My suggestion would be to open same page on both servers, and compare what are they delivering to you. Start with page source i.e. Right click on page, "View page source", and save into file. Then use some tool to compare those 2 sources. Check for differences....
Then you can use Firebug or similar tool to check are all page resources (as mentioned, CSS, JS images...) loaded well. If all is ok so far...then you have to compare resource files too. Start with CSS maybe...then go to JS.
It's tedious work...but without additional info that's the best advice I can give you.