Body: <p>I'm using Wordpress 4.9.9 and CiviCRM 5.4.1. Earlier today I updated several plugins, everything works fine except Civi.  </p>
  
  <p>** UPDATE: With civi activated, I get a blank page any time I try to edit a Wordpress page. </p>
  
  <p>I also get a blank page when I try to go to the Civi dashboard in Wordpress and I cannot access any Civi pages such as event registration or membership pages. </p>
  
  <p>In a Wordpress log I get:</p>
  
  <pre><code>2019-02-14T22:19:10+00:00 CRITICAL Uncaught CRM_Core_Exception: [0: Invalid 
  cache key: Not a string
  
  thrown in /var/www/vhosts/&lt;site&gt;/httpdocs/wp- 
  content/plugins/civicrm/civicrm/CRM/Utils/Cache.php on line 236
  </code></pre>
  
  <p>That code is in the assertValidKey function. </p>
  
  <p>Any ideas on where to go from here?</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-02-19T13:54:12.863Z
Comments.Text: Is this reproducible? If so, can you log what the cache key is at that point in the script?
Comments.UserDisplayName: Christian Wach
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-07-28T17:40:59.070Z
Comments.Text: How was this issue fixed ? I have upgraded recently to 5.15.1 but it shows me error as well and site is down due to this
Comments.UserDisplayName: harshal
Tags: <wordpress><dashboard>
Title: Fatal Civi Error: "Invalid cache key: Not a string" error in Wordpress
ThreadText: # Fatal Civi Error: "Invalid cache key: Not a string" error in Wordpress
  
  (Asked by: username_0 on 2019-02-14)
  
  I'm using Wordpress 4.9.9 and CiviCRM 5.4.1. Earlier today I updated several plugins, everything works fine except Civi.
  
  \*\* UPDATE: With civi activated, I get a blank page any time I try to edit a Wordpress page.
  
  I also get a blank page when I try to go to the Civi dashboard in Wordpress and I cannot access any Civi pages such as event registration or membership pages.
  
  In a Wordpress log I get:
  
  ```
  2019-02-14T22:19:10+00:00 CRITICAL Uncaught CRM_Core_Exception: [0: Invalid 
  cache key: Not a string
  
  thrown in /var/www/vhosts/<site>/httpdocs/wp- 
  content/plugins/civicrm/civicrm/CRM/Utils/Cache.php on line 236
  
  ```
  
  That code is in the assertValidKey function.
  
  Any ideas on where to go from here?
  
  **Tags:** wordpress, dashboard
  
  > **Comments:**
  > **username_1**: Is this reproducible? If so, can you log what the cache key is at that point in the script?  
  > **username_2**: How was this issue fixed ? I have upgraded recently to 5.15.1 but it shows me error as well and site is down due to this  
  
  ---
  
  ## 0 answers
  
  