When trying to reinstall with latest version i get the error as copied below. The initial setup seemed fine, but then it gets stuck at this point just after pressing Go.

Fatal error: Call to undefined function filesystemToInternal() in /homepages/22/d401692478/htdocs/zp-core/functions.php on line 597

Any idea what i may be doing wrong?

Thanks

Any other errors? Permissions maybe?

Tried again including file permissions set to 'relaxed 0664', but still the same error.

The described error is the only one encountered. After initial setup and click 'Go' the process starts with: Tables are updated, mod_Rewrite and then Theme Setup are checked, when it stops with the fatal error.

Whilst this is the only Error displayed, there are some 'Warnings' during the initial setup. From what i can guess these Warnings (e.g. PHP and MySQL versions a bit older but within acceptable range, Theme files seem missing...) are not related to the Fatal Error later on, but there is one such Warning that does mention Permissions:
"Zenphoto suggests you make the sensitive files in the zp-data folder accessable by owner only (permissions = 0600). The file permissions for security.log are 0660 which may allow unauthorized access."

Any other ideas what to check for?

Thank you

All those are warnings and should not be related. Don't remember to have ever seen this. But could be related to this reported bug: https://github.com/zenphoto/zenphoto/issues/844

Reverting back to previous version via backup was not possible - running setup was necessary, but did not run at all.

Another new attempt with current latest version again produced the same error as described above - however, i am now able to access the backend and all admin tasks and configuration seem to work and behave normal, and so does the site, despite the incomplete setup with error - is this what you would expect?

No, of course not.

Under "re-installing" I understand re-uploading all files again (except albums naturally) and re-running setup. That should not cause any issues.

Please explain exactly what you did on re-installing and post any other error or warning from the error log (the server one). In case a detail is missing.

Reverting back to previous version via backup was not possible - running setup was necessary, but did not run at all.

You mean a downgrade? No since the database etc might have changed. If you mean the database backup utility that only works with the exact same version actually.

Not quite true. The database backup utility will restore from prior versions. BUT, if there has been a significant change in the database, no migration is done. This is why we recommend always restoring from the original version.

BUT, if that is not possible, maybe the restore will work, at that point you have nothing to lose by trying.

Sorry, i guess my description and terminology was not clear and precise enough.

My old setup was with version 1.4.5.9, which I was trying to upgrade to current latest version 1.4.6.
However, in addition to folders zp-core, themes and index.php i had also removed other folders cache and zp-data from my old setup.
Perhaps what i was trying is more like a re-install and upgrade to a newer version at the same time?
Anyhow, I first described my attempted upgrade as a "reinstall", as this is the term that is used at the top of the setup page.

During the setup there are a number of warnings, as described earlier (would still assume these are not related to the error encountered).

After the setup stopped with the fatal error as described, i tried to revert back to my old previous setup, i.e. i was trying to run a setup with a full backup copy of all (old version 1.4.5.9) files and folders (not just database). This produced a message of critical changes detected requiring to run setup, but, this setup was not possible with the setup page not being displayed at all.

Trying anew to upgrade/reinstall v 1.4.6 as described the initial setup seems fine again, including a number of Warnings (which still seem not related to the error encountered later on?).

One correction though - there was 1 other Error during this initial setup about possible "php messages being displayed on web pages", which is turned into a Warning after acknowledging the error. (btw How can i prevent display of php messages on web pages?)

After the initial setup and pressing "Go", the auto setup routine begins to run and does complete tables and theme checks, after which it gets stuck with the Error as described previously.

However, and despite this incomplete setup - i can access the admin page and all seems to function normal, at least from all what i can see so far.

Thanks for the details. It should not harm to remove the cache and zp-data folders. The latter is part of the package, too, so normally is uploaded.

Although you don't need to remove those two folders on an upgrade at all. The config file in zp-data will be just used. You only need to replace zp-core, the official themes within the themes folder and the root index.php file (as described on the installation page).

If you remove zp-data it is a kind of reinstall but if the database is still there all that is actually different is that you have to re-enter db credentials to re-create the config file. All else is an upgrade therefore as also the admin user is still there to login.

I quickly just deleted the zp-data folder on a local test install to do the same. I could not reproduce your error but again only could reproduce this ticket: https://github.com/zenphoto/zenphoto/issues/844

(btw How can i prevent display of php messages on web pages?)

Depends on your host. You can set that via htaccess, a php.ini or via php.

Hello,

I've got the same error and I've open the function_basic.php file and filesystemToInternal function is not defined in it, is it normal ?

Ludm

Yes that is correct. The function is defined further downstream, in functions-common.php.

Try re-uploading the zp-core folder. Maybe a file got corrupted during the initial upload.