Solved: WordPress Admin Internal Server Error 500 after Update to 4.8

When I hit update on my WordPress 4.7.4 to update to 4.8 it almost instantly returned me an error 500 – Internal Server Error when trying to access WordPress admin area (wp-admin). This led me to a troubleshooting procedure and a lot of Googling (that didn’t help).

Internal Server Error 500 accessing WordPress admin - HostGator hosting
Internal Server Error 500 accessing WordPress admin – HostGator hosting

How did I solve it?

Internal Server Error 500 usually means that the .htaccess file is corrupt, something is wrong with file permissions, scripts are being unallowed to load etc.

The site where it happened was hosted on HostGator. To solve I tried all the options including:

  • removing .htaccess file
  • disabling plugins (just rename the plugins directory)
  • disabling themes (rename theme folders)
  • seeing WordPress errors log
  • re-uploading core files from a fresh installation

Finally the solution was a surprising one. I consulted the error log in HostGator-s Cpanel.

HostGator Cpanel error log access
HostGator Cpanel error log access

 

From there I could see errors saying files wp-admin/index.php, wp-login.php etc were writeable by group.

Error log - WordPress core files writeable by group (HostGator error log from Cpanel)
Error log – WordPress core files writeable by group (HostGator error log from Cpanel)

 

I logged in to my installation via FTP and saw that indeed, files had 666 permissions rather than 644 that are suggested as WordPress standard.

666 permissions for files in WordPress after update to 4.8
666 permissions for files in WordPress after update to 4.8

SOLUTION

I simply selected all the files in wp-admin folder and then all the files in root folder and did a filesystem permissions update on them to 644.

Change filesystem permissions from 666 to 644 for files in WordPress
Change filesystem permissions from 666 to 644 for files in WordPress

 

After running the update on the files’ permissions, the login screen appeared and I was able to log in.

WordPress wp-admin login working
WordPress wp-admin login working

 

That’s how I solved WordPress admin giving Internal Server Error 500 after updating from 4.7.4 to 4.8.

Hope this helps someone struggling with the same error/issue!

Post Author: Tom Pai