Fatal error: Call to undefined function finder_ui_info() in /****/sites/all/modules/finder/modules/finder_ui/plugins/export_ui/f

First of all, I'd do a quick check for integrity of files in modules/finder_ui/includes - do file sizes match these?

(By the way, another one of your issues - #1932538: 500 error after updating from 7.15 to 7.20 - sounds pretty much like broken file, too)

If common.inc is OK, could also try the attached patch.

(This normally should not be needed as finder_ui loads finder.inc which in turn loads common.inc - so this is just trying to play it safe)

Being an old-school text editor user, I'm not really familiar with NetBeans;
but the potential fix I have in mind is a one-liner anyway, so we might as well insert it manually.

To recap the background:

• that finder_ui_info() function that the error is about resides in /modules/finder_ui/includes/common.inc;
• finder_ui.class.php makes sure to load finder.inc, which in turn loads common.inc;
• the function used for loading is finder_inc() which in turn uses ctools_include() which in turn uses PHP's require_once;
• somewhere in the process, something goes wrong; if the file was not found, the whole script would break down even earlier, so I strongly suspect it somehow finds a wrong file (there are several common.inc around in different directories);
• as it works for most users (including me), there might be something about your environment.

Based on this, my suggestion is to try loading the right file more explicitly by adding a line

    require_once DRUPAL_ROOT . '/' . drupal_get_path('module', 'finder_ui') . '/includes/common.inc';

after line 17 of finder/modules/finder_ui/plugins/export_ui/finder_ui.class.php (between finder_inc() and ctools_include() calls).

Also, are there other suspicious errors in 'Recent log events'? E.g. along the lines of 'Failed to open stream (...)'.

No activity for four weeks - I reckon the OP either gave up or found another solution/workaround (if this is the case, you're welcome to share it).

I for one could not reproduce this from the start.