HTTP 503 Error - installation

I tried to install Owncloud and use this script to make the update :

Owncloud works.
After update, Nextcloud works.
I close Chrome.
I open my cloud.
HTTP 503 Error.

Weird thing : when I use the private nagivation on Chrome, Nextcloud works like a charm
I ve tried to delete all my cookie/cache ect… on Chrome. Its working. But when I close and reopen again, its down again