crash update wordpress

One of my websites was running version 3.70, ok update to 3.7.1

Unfortunatly my hoster has a strange idea, php 5.3 cli has the habbit to set rights to Apache from time to time, not always.
Do you see the clue already ?

Exactly, during update WP : stops. Examining hostingdashboard, a few directories on Apache. Simple to set these back to user.

But ….. start again update ? No
Inlog to start it manually : No
Inlog in common : No
change password asking mail: Yes, changed, checked by adminer ..: Yes
can I login : No

And so on and so on.
Strange ……. login.php shows the strenght bar, doesn’t work
Strange ……. login.php shows after visiting directly an error message in red window holding :
FAILURE: Invalid username or email address.

Visually, the site is ok for visitors, nothing to see. WP runs in the root, no subdir.

Someone with a brilliant solution ?