Quickly creating an issue for this; proper issue summary will follow.
https://www.drupal.org/docs/8/upgrade/upgrade-using-web-browser#pre-upgr...
If the database credentials to your source database are correct, the upgrade review page will appear as illustrated in the screenshot below. This page shows a summary of the upgrade status for all installed modules on the old site.
Latest iterations use this help text instead:
The new site is missing modules corresponding to the old site's modules. Unless they are installed prior to the upgrade, configuration and/or content needed by them will not be available on your new site. Read the checklist to help decide what to do.
Recent comments
It looks like the minify module is not properly processing your JS and HTML files. Have you checked the file paths and permissions to ensure they are accessible? I remember, that once I faced...
Minify
This looks like a great initiative. Keep rocking mate!
New website: FirstTimeWatching.com
I figured the space part of it out, but caption length is still limited to about 125 characters. - #CboxContent: margin-bottom expands it just enough and doesn't disrupt the counter or arrows...
Longer Captions with Colorbox?