Update InvoicePlane 1.5.9 to 1.5.10

What is the correct procedure to update InvoicePlane from 1.5.9 to 1.5.10?

InvoicePlane 1.5.9 is now running on a Windows server correctly, when I follow the update procedure on Wiki I get different errors like line 143 in session.php windows temp map not writable. The # or // solve the problem but then I cannot login, that is correct because I outcomment the login procedure…

What I do:
InvoicePlane 1.5.10 in a new map
Edit the ipconfig.php with new settings to a new database ( copy of old one ), setup disable and correct new URL…
Copy database.php file
Copy uploaded .png files in upload map

Kind regards,

Arno