Hi @ all.

Recently I installed ZPC on a local machine, running with DebianEdu "Stretch".
The overview information in the backend complains only that "Locale setting has failed", no spam filter and "no mail handler configured".

The problem I am facing is, that I am not able to save edits in the database when e.g.:
I modified
picture titles or descriptions,
album titles or descriptions.
I press "Apply", and Browser says: "Changes applied"
but the earlier filled fields are empty now.

When editing
Options - Gallery - Gallery title or description,
I click "Apply" and the browser says: "Applied", but then the formerly filled fields are empty again.

Any ideas?

Thanks.

"Locale setting has failed"

That is not important if you don't intend to use any other language than the native English on the backend or multilingual sites.
If you wish to do that your server needs support for this and the native PHP gettext extension.

no spam filter

No error, just no plugin for this is enabled.

no mail handler configured

Just enable one of the two email plugins.

On your issue regarding content not saving please review your server's PHP error log.

Regarding: "The overview information in the backend complains only that "Locale setting has failed", no spam filter and "no mail handler configured"."
This was just mentioned to say, that the server settings should be fine.

Regarding the problems why I opened this topic:

PHP-Error.log: I have no clue where to find it within DebianEdu.

"normal" error.log has following entries:
[Mon Jan 15 16:26:45.050980 2018] [:error] [pid 4327] [client ::1:56466] script '/etc/debian-edu/www/zenphoto/zp-core/zp-extensions/zenpage/admin-upload.php' not found or unable to stat, referer: http://localhost/zenphoto/zp-core/zp-extensions/zenpage/admin-news-articles.php?publish=1&titlelink=erste-gschichte&XSRFToken=cd3b93f3501aa85ac16674963560117eb37a4762
and
[Mon Jan 15 16:26:58.056133 2018] [:error] [pid 35151] [client ::1:56468] script '/etc/debian-edu/www/zenphoto/zp-core/zp-extensions/menu_manager/admin-upload.php' not found or unable to stat, referer: http://localhost/zenphoto/zp-core/zp-extensions/menu_manager/menu_tab.php?page=menu&tab=menu

That actually looks like a PHP server error log.

The first url reported by the two errors is totally wrong and not supposed to exist at all. admin-upload.php is within zp-core directly.

It seems that something is really not right on your install or server. I cannot help with actual server configuration and have no knowledge about Debian itself but make sure you have installed everything correctly if you do this yourself. Zenphoto generelly works on standard shared hosting out of the box.

The first to check would also be wrong or too strict file/folder permissions as that is known to cause any sort of issues. Please see the user guide for the recommended ones.

I think it has something to do with the right management.

The folders are on 777 now (local install)
I've disabled all plugins.
Restarted apache, logged in as Admin and still the problem exists.

When modifing e.g. an user-album description as admin and "Apply" it, not only that it "forgets" the admin's edit - it also deletes the earlier content of "album title".

Using a different browser (konqueror), logging in as this particular user, and edit the content of "my" user-album - these changes are entered in the database.

I have - now again - "played" with album edits as admin and there is no entry in the error.log.
Maybe upper entries were caused by an earlier active plugin...

If konquerer works it is probably the other browser. Probably some of your plugins are blocking things unwantedly as you encountered on the forum yesterday. So disable every plugin you are using. If it then works it is one of these plugin.

I am using different machines with different setups and different browsers(settings).

Meanwhile I made a new, clean install and upper problem does not appear anymore.
So, one of the plugins - (and it's left overs) may have caused this mailfunction.

I will activate needed plugins with this new install successively and I hope - if the problem shows up again - that I can locate the "bad guy".

Thank you for your assistance! I appreciate it.