Update from 8.1.3 to 8.1.7 gives me a fatal error on most pages

Question

After attempting to update to version 8.1.5 I received the

• "The website encountered an unexpected error. Please try again later."

error on many pages. I also get the following error in Recent Log Messages;

• "Drupal\Component\Plugin\Exception\PluginNotFoundException: The "2" plugin does not exist. in Drupal\Core\Plugin\DefaultPluginManager->doGetDefinition() (line 52 of /home/username/public_html/domain/core/lib/Drupal/Component/Plugin/Discovery/DiscoveryTrait.php).

Any ideas what could be causing this or how to fix it?

Update 2016/07/20

I just tried once again to update from 8.1.3 to 8.1.7 and am getting the same errors. My 8.1.3 site was stable with no errors.

Specifically, the site has the following issues after updating and after running update.php several times.

• non-admin users can't log in; they receive the white screen of death upon login attempt, and can't even navigate to a different page than the default user page. The can only successfully logout using /user/logout to get back to the working frontpage and other working content pages.
• when logged in as admin, eveything seems to work except for the "extend" and "people" admin tabs, which result in a wsod.

The reports details show the following information after an unsuccessful attempt to access;

---

Type php

Date Wednesday, July 20, 2016 - 08:09

User admin

Location http://www.domain.com/admin/people

Referrer http://www.domain.com/admin/config/people/accounts

Message Drupal\Component\Plugin\Exception\PluginNotFoundException: The "2" plugin does not exist. in Drupal\Core\Plugin\DefaultPluginManager->doGetDefinition() (line 52 of /home/username/public_html/domainfolder/core/lib/Drupal/Component/Plugin/Discovery/DiscoveryTrait.php).

Severity Error

Hostname @@@.@@.@@@.@@@

Operations

---

Type page not found

Date Wednesday, July 20, 2016 - 11:34

User admin

Location http://domain.com/quickedit/metadata

Referrer http://domain.com/node/preview/aabc334a-08fb-4d6a-8672-281dbe7a56e6/default

Message /quickedit/metadata

Severity Warning

Hostname 113.37.159.155

Operations

---

Type php

Date Wednesday, July 20, 2016 - 11:25

User admin

Location http://domain.com/node/add/lesson

Referrer http://domain.com/speakraku

Message Warning: mkdir(): File exists in Drupal\Component\PhpStorage\FileStorage->createDirectory() (line 165 of /home/username/public_html/domain/core/lib/Drupal/Component/PhpStorage/FileStorage.php).

Severity Warning

Hostname 113.37.159.155

Operations

Answer 1

Fixed - tracked the problem down to the dev version of field permissions I was using. Updated to the latest dev version and all related issues were resolved.