ajax loading error: not found

[abtin1980]

Hi,
This is the error message when I'm gonna update joomla 3.8.6 [PHP version: 5.6] :
ajax loading error: not found
Screenshot attached.

What I've done up to now:
* I've tried "Fix Permission" command with "Admin tool pro" but unfortunatelly doesn't work.
*Rename .htaccess
*check PHP Information:
max_execution_time = 9000 and memory_limit = 1024M
Frankly I'm exhausted.

[abtin1980]

Please someone help me out!!

[abtin1980]

I'm using "AJAX Live Search results" plug-in, is it possibly any relation between this plug-in or this error?!

[abtin1980]

[Solved]
Unbelieveable man.
1- Download latest version of joomla.
2- Extract this folder: administrator/components/com_joomlaupdate
3- Replace it in this folder: /public_html/administrator/components/com_joomlaupdate
*[When I mean replace, it means replace folder and it's subfolders]
4- Update the joomla normaly.

[mikefitz]

**Solved** I found on several domains on my server, the administrator/components folder permissions were set to 777 rather than 755. When I changed to 755 the error was eliminated.