Silvio, can you please download, unzip and upload the attached file into the following folder then try again:

admin/model/common

Regards

Hi Denis,

now I got:
Update process has failed, please, try again.

Tried it some times. error.log shows no information.

Any idea?

From the system information you provided and the return after the change we made I can say that the problem is with file/folder permission of the local host. The apache2handler Server Interface (SAPI) is well known for such issues:

https://docs.joomla.org/Security_Checklist/Hosting_and_Server_Setup#PHP_Being_Run_as_an_Apache_Module.

Regards

chmod 2757 on all folders might help on those crappy servers, I would only use it temporary though, and reset to 2755 after updating ...
Changing hosting is the best, host running this setup today shouldn't be hosts, imho ...

Thanks for your posts. I've changed some server settings in my local testing environment (XAMPP). So now the parameters are:

Setting 	Value

Platform 	Arastta 1.3.1 Stable [ Kastamonu ] 29-April-2016 14:00 GMT +2

PHP Version 	5.5.11

PHP Built On 	Windows NT LAPTOP 6.1 build 7601 (Windows 7 Home Premium Edition Service Pack 1) i586

Database Version 	5.6.16

Database Collation 	latin1_swedish_ci

Web Server 	Apache/2.4.9 (Win32) OpenSSL/1.0.1g mod_fcgid/2.3.9

Server Interface (SAPI) 	cgi-fcgi

User Agent 	Mozilla/5.0 (Windows NT 6.1; WOW64; rv:46.0) Gecko/20100101 Firefox/46.0



Folder 	Status

admin 	Writable

catalog 	Writable

download 	Writable

image 	Writable

system/cache 	Writable

system/log 	Writable

system/modification 	Writable

upload 	Writable

vqmod 	Writable



Setting 	Value

Safe Mode 	Disabled

Register Globals 	Disabled

Magic Quotes 	Disabled

File Uploads 	Enabled

Session Auto Start 	Disabled

Session Save Path 	D:\xampp\tmp

Display Errors 	Enabled

Output Buffering 	Disabled

GD 	Enabled

cURL 	Enabled

mCrypt 	Enabled

ZIP 	Enabled

Zlib 	Enabled

Mbstring 	Enabled

Iconv 	Enabled

Open basedir 	

Disabled Functions 	

So Server Interface (SAPI) now via cgi-fcgi. Nothing changed. It founds the update from 1.3.1 to 1.3.2 but threw the error:
Update process has failed, please, try again.

Folders are writable and no errors were logged. Any idea?

Folders are writable and no errors were logged. Any idea?

What is the chmod on main folders, sub folders and files?
Do the web user have write access to to folders and files?

Even if you changed server settings, there might be old issues staying behind.
Have you tested updating a fresh install of a older version, in a new web root made after server changes (or running chown -r to correct existing)?