Hello,
I've upgraded 2 days ago to latest version 1.4.5.1 without errors, but since yesterday I have no access to folder zp-core. On Firefox or Chrome I have a blank page and I don't understand why.

For the upgrade, I've changed the zp-core folder, the zenphoto index and the default themes (not including my theme zpArdoise).

Any idea what it could be?

Thanks

What exactly do you mean with no access to zp-core? The backend? Blank page means mostly either file/folder permissions issues or fatal php errors. What do the logs say?

My post was deleted..

I mean when I go to mywebsite.com/zp-core, I don't have the login page displayed but only a blank page. There is no error information displayed.

I checked the folder and files permissions and it seems ok (read and write permissions).

How can I access the logs other than by the administration page?

Regarding the deleted post see the sticky on the forum.

Login is yourdomain.com/admin or youdomain.com/zp-core/admin.php.

TheZenphoto logs are within /zp-data. For the server logs please aks your host.

Ok it works with yourdomain.com/admin!

Sorry, I didn't see there was a new path for admin.
Thanks!

That one is not new actually. There is just no index.php page anymore so just zp-core does not work anymore (security measure).