Update doesnt work

Hi
i tried to update from Woo 4.0.2 to Version 6.0.0 (on a WP Installation with WP 5.8.2)
– I clicked on update
– The woo-window open with the list of compatibilies and the message that this is a mayor update
– i click the pink button to “realy update”

Nothing happened.
Even after 20 minutes nothing happened and WP said its still woo 4.0.2.
I tried again.
Now i cant login anymore cause WP is in maintenance mode.
I wanted to fix it by deleting the maintenance file that usually is in the root directory – but there is none.

What now please?

kind regards
axel