"error unable_to_check_admin_permissions" ajax error

[alex.smart]

I'm getting this error on all of the site builder buttons apart from AdminCP.

These are the logs from console when I switch the site builder on.

 vBulletin.loadingIndicator.show Counter: 1 Source: ajaxStart
  
 			POST http://mysite/ajax/render/stylesheet_block
 			500 Internal Server Error





  vBulletin.loadingIndicator.hide Counter: 0 Source: ajaxStop

And when I click on the Page Manager Button...

 Securitytoken updated
  vBulletin.loadingIndicator.show Counter: 1 Source: ajaxStart
  
 			POST http://mysite/ajax/api/options/fetchValues






  Error when fetching options: Internal Server Error
  vBulletin.loadingIndicator.hide Counter: 0 Source: ajaxStop
  vBulletin.loadingIndicator.show Counter: 1 Source: ajaxStart
  
 			POST http://mysite/ajax/api/options/fetchValues






  Error when fetching options: Internal Server Error
  vBulletin.loadingIndicator.hide Counter: 0 Source: ajaxStop
  Fileupload: vBulletin.upload.initializePhotoUpload
  Fileupload: vBulletin.upload.initializePhotoUpload finished
  vBulletin.loadingIndicator.show Counter: 1 Source: ajaxStart
  
 			POST http://mysite/ajax/api/user/currentUserHasAdminPermission
 			500 Internal Server Error





  ajax/api/user/currentUserHasAdminPermission error: Internal Server Error
  
 			POST http://mysite/ajax/api/phrase/fetch
 			500 Internal Server Error





  Error when fetching phrases: Internal Server Error
  
 			POST http://mysite/ajax/api/phrase/fetch
 			500 Internal Server Error





  Error when fetching phrases: Internal Server Error
  vBulletin.loadingIndicator.hide Counter: 0 Source: ajaxStop

[alex.smart]

The php5 version download doesn't work, using default .php version which works with the site builder.

[Wayne Luke]

The recommended extension is PHP. Using the others is reserved for advanced users that know how to configure their web servers to work with them. Using the php extension allows it to work on 98% of servers out of the box.