Rich,
For the first post, when you move the site local, you said:
If I enable the same plug-in on local server you cannot view the site, no page is shown and you cannot reach to administrator page.
What happens when you try to visit the administrator page? Is there an error message at all? Can you go to the Joomla Global Configuration and turn off GZip compression and set Error Reporting to 'maximum'? That may provide a clearer message of what's going wrong.
We test and develop on a local site site, so running locally certainly shouldn't be an issue.
Image selection in Content Plugin
The newest version of the Content Plugin, v4.3.3, will try more aggressively to pick an image for your Joomla article pages. If you've created an "Open Graph Object" for the category the article is in, we'll use the image setting you've chosen there (first image in article text, category image, or custom image parameter). If you haven't set an Object type, or the setting for the image for that article isn't working, JFBConnect will try the following until it finds an image to use:
* Pick the first image from the article
* Pick the category image setup in Joomla
* Use the default image set in JFBConnect
So, we'll try more things, but if there's no image in your article or your category doesn't have an image, we have no other options but to use the default image or no image at all.
If that's not working for you, let us know a page where the image isn't being used, but there is one in your article. Also let us know how the image is being inserted into the article (inside the article text or some other method of specificying the image).
Thanks,
Alex