I am enabled XMP metadata, and then started Refresh Metadata.

It runs for a few seconds, then I get

This page isn’t working
cms.waltrips.com is currently unable to handle this request.
HTTP ERROR 500

No errors in debug log

IN apache log:

[Thu Mar 11 09:45:02.412222 2021] [php7:error] [pid 2991451] [client 192.168.1.104:61653] PHP Fatal error: Maximum execution time of 30 seconds exceeded in /var/www/cms.waltrips.com/zp-core/zp-extensions/xmpMetadata.php on line 674, referer: http://cms.waltrips.com/

The error means a script took longer and timed out. Could mean to many images and albums to refresh or the already noted "wrong" or "corrupted" meta data issue.

To rule out if is the XMP metadata disable it and try again. Since it involves extra operations that might be just too much for your server.

There is nothing in the debuglog because the issue was earlier than that. Btw, that's the PHP error log actually and actually not the apache log. That would be about requests and such.

Without xmpmetatdata I get about 4 of these:

{2991448:Thu, 11 Mar 2021 14:59:08 GMT}
NOTICE: Uninitialized string offset: 1 in /var/www/cms.waltrips.com/zp-core/exif/makers/gps.php on line 82
formatGPSData called from parseGPS (gps.php [216])
from read_entry (exif.php [830])
from read_exif_data_raw (exif.php [1036])
from read_exif_data_protected (functions.php [2451])
from Image->updateMetaData (class-image.php [340])
from Gallery->garbageCollect (class-gallery.php [818])
from admin-refresh-metadata.php [33]

Again your wrong geocoordinates apparently.

is there a way I can tied this back to the photo that cause this?

Also... not seeing PHP errors.. Just turned on logging in PHP

is there a way I can tied this back to the photo that cause this?

You can enable debug modes but I don't think that will help here. Unless you want to code try refreshing by album to at least find the album causing this.

Also... not seeing PHP errors.. Just turned on logging in PHP

Yes, that's fine that way.

However I will take a look at the line to perhaps catch that undefined array index/offset. But the base issue is that the image metadata apparently tells to have data it doesn't.

thanks on the coding... I write in powershell, and at the end of the day have to anticipate when bad data happens and put in checks for it. It is almost imposable to anticipate when you will get bad information sometimes.

As to refreshing comment... If I refresh album by album (go to album, click on "refresh album data", that will only refresh the album and not the whole gallery?

Yes, we user "gallery" as term for all albums respectively the whole site.

OK... if I scan albums with my fuji and nikon photos..., Neither of which have GPS data, it scans them

If I scan an album with photos from my Samsung Galaxy Note 10+, it times out. I don't know if this related to Samsung pictures, or GPS.

if I disable XMPMetadata plugin, then refresh works everywhere.

I can send you sample pics if need be,

It might very well be the image size. Are these larger than the others perhaps? After all the files are loaded to be read. Also for now do you need XMP at all? Most certainly the EXIF data has the same info.

Do I need XMPINFO to read sidecar files?

Do I need XMPINFO to read sidecar files?

What sidecar files? Xmp sidecar files? Yes, of course. But your images have these metadata most likely embeded.

Metadata of ZP sidecar files (video thumbs etc.) is not read anyway.

I was looking at the ability for albums to store text in such a way that it could be put back in case I delete and recreate the album - not critical

do sidecar files work with JPEG and videos? I was looking fo rthe same there... being able to take text such as detailed description and store it with the JPG or M4V and have it read. will xmpmetadata not do that?

does xmpmetadata support sidecar files for jpeg?
do I need it for sidecar files, or is that supported without it?

If you mean XMP sidecar files, yes, as that is the purpose of this plugin if you read its description.

OK. I did... I understand. just making sure I did not miss anything.
As to image size they are 3.7 to 11mb in size.

Still trying to figure out why things go haywire when I enable xmpmetadata.

Well, it does extra processing. So again the question do you need it actually? If the metadata is embeded in the images it is not as it is read and stored in the database anyway.

I assume it only does extra processing when refreshing metadata, correct?

if that is the case, it would be fine... I don't run that but periodically. then issue is it is timing out.

I assume it only does extra processing when refreshing metadata, correct?

And on initial discovery of an image of course. Again, you don't really need the XMP plugin if meta data is embedded tto the image. XMP is an extra set most likely standard EXIF and/or IPTC data is also there.
It's always good to only use the plugin really needed (besides any timeout)