unresponsive "edit" button on posts page, plus other things

Hi all, I’ve recently been put in charge of my workplace’s dormant WordPress and the WordPress dashboard is giving us grief. Our main blogger left the company a few months before I started. We recently updated to 4.2.4 if that helps, but I can’t recall from what version we updated. The problems I’ll describe were present during the last version we used.

Our current problem is that we have several posts saved as drafts, but when we click on the “edit” button, it simply takes us back to the “posts” page without opening the editing screen.

There also seems to be something weird going on with the “Preview” function on the same page. Instead of calling up the post, it just takes you to the front page of our blog.

Additionally, when an administrator attempts to edit an existing user, we are taken to an invalid ID page. This even happens when we attempt to edit our own user profiles, despite being able to log in and all that good stuff. I’m not sure if it’s related, but it’s a problem occurring alongside the big one.

I’ve tried running it clean without any of our plugins, but to no avail. I was wondering if this is a problem that people have run into in the past, and if there’s something obvious I’m missing. I’m a tumblr and blogspot user primarily, so that gives you an idea of what I know.

A list of all our plugins with versions in parentheses:

Add Multiple Users (2.0.0)
Aksimet (3.1.3)
Antispam Bee (2.6.7)
Broken Link Checker (1.10.9)
Edit Flow (0.8)
Google Analytics by Yoast (5.4.5)
nrelate Related Content (1.4.0) DEACTIVATED
Outbound Links (2.0.1)
Redirection (2.3.16)
Search Everything (8.1.3)
Sharebar (1.4)
Simple 301 Redirects (1.06)
Social Sharing Toolkit (2.3)
Storify (1.0.9)
Subscribe to Comments Reloaded (150611)
WordPress Database Backup (2.3.0)
WordPress Importer (0.6.1)
WP Most Popular (0.2)
Yoast SEO (2.3.4) DEACTIVATED

Thank you all in advance! Have a good one!