Hello frosticek, I finally after 2 re installs of Osclass and Zara theme did get the Google Connect Plugin to work, (also FB) I mean, following all the directions of the plugin. That was friday night. That was the first plugin to install and everything worked out just fine. Today I had to delete that instalation because of change of domain name and installed all plugins, did set up of all, categories, location settings, everything, and when I tried to use the Google login, alas, it won't let me log in, it just shows the permit window of Google, and then after click ok allow, it sent me again to the homepage of my site. (same with Facebook login button). and yes, all the instructions were followed step by step.

My guess is that maybe some other plugin is making noise. Please advise.

I send you a link of a small video I made to show you this.

Please don't respond just saying that I didn't follow the instructions, I did. You're the expert, I'm not. 

Thanks.


https://youtu.be/Abzh_HKKNBs

@Daniel PM
There are some tips in plugin settings, did you go through all of them?

Important note
If you have set up everything and you still has problem that after click on login button, you are redirected back to homepage with no result, place following code into first line of your head.php:
<div style="display:none;"><?php gc_login_button(); ?><div>

Hello frosticek, I did that and right after saving head.php file and loading the website, it does not show any part of the webpage, all blank, I removed that code and the page shows again normally. Is there another php file where I would put that code?

Thanks

@Daniel PM
Sorry, there is typo, correct code is:
<div style="display:none;"><?php gc_login_button(); ?></div>