Great sleuthing John! It is quite funny that at the coordinates that are closest to the same date and time, you find a small square with parked cars behind a church so I didn't even question it or check street view. But yeah 23 hours and 20 minutes off is exactly right and Lightroom is doing the exact right assignments with that file and that gpx track. The issue is not caused by a timezone offset even though that is still something people should remember if you are auto-tagging in a different timezone than where you shot the images. So in this case, either the timecodes in the gpx file are completely wrong, or the camera's date and time was set completely wrong. I would suspect the camera must have been off as the gps app on the phone would normally get the correct date and time and timezone from the local cell tower and therefore should always have the correct date and time.  It is weird though that the app Jack used to tag somehow does do the correct assignments even with this enormous time difference. That really should not be possible with that raw file and that gpx file. but perhaps it autoshifts the time when you give it a bunch of images at a time with the same timespan as the gpx track?   P.S. to Jack, the gpx track contains what is likely exactly your address in Glasgow. perhaps don't leave the file on dropbox or delete the points for October 3rd in the last two segments. These files are just xml text files that you can edit in any text editor. Just delete the last two track segments on October 3rd. ... View more

And a further comment. I noticed that the gpx file contains nonstandard tags like this: <!-- TZ: 7200 -->. The <!-- TZ: 7200 --> tag might indicate that it is offset by 7200 seconds which of course is two hours, which is the timezone offset in Italy vs UTC. So that is where the two hours offset is coming from I described above. The <!-- TZ: 7200 --> is something that is not part of the gpx file standard that your geotagger app is doing. It should just write the times in UTC instead. Not sure why that app is doing that. None of the gpx files I have contain tags like that. ... View more

The gpx file has times in UTC timecodes (that's the gpx standard). You can see the correct coordinates in the gpx file are between these two points: <trkpt lat="43.318241" lon="11.329464"><ele>335.310364</ele><time>2025-09-23T09:17:22Z</time></trkpt> <trkpt lat="43.318241" lon="11.329464"><ele>335.310364</ele><time>2025-09-23T09:22:23Z</time></trkpt> On google maps that is these coordinates: https://www.google.com/maps/place/43%C2%B019'05.7%22N+11%C2%B019'46.1%22E/@43.318241,11.3268891,1125m/data=!3m2!1e3!4b1!4m4!3m3!8m2!3d43.318241!4d11.329464?entry=ttu&g_ep=EgoyMDI1MTAwMS4wIKXMDSoASAFQAw%3D%3D On the piazza San Giovanni right next to the Duomo Di Sienna.  The Raw file indicates it was taken on 2025-09-23T09:20:23.11 in the local timezone. You can see that that appears to be correct with the two points above, however the gpx file uses the UTC description (that's what the Z at the end of the timecodes means) so that actually makes the time 2 hours off in the file! Italy in summer is two hours difference from the UTC standard (UTC is basically GMT).   Was it 9:20 am local time when you took that picture? If so the coding in the gpx file is wrong indeed. If it was actually 11:20am when you shot the picture the time coding in the gpx file is correct.    I discovered where the 6 hours come from. That is the timezone on my computer which is in the UTC/GMT-6:00 timezone. So the offset for you is going to be different. The problem is that Lightroom assumes that when you import an image, it was taken in the timezone your computer is set to. So with the (apparently wrong timezone coding in the gpx file and the fact that I am in the USA Denver region, that results in a 6 hour offset. For you in Britain, it should be a 1 hour offset that you need to dial in.   So I think there are one and maybe two issues. One, the assumption that Lightroom makes that imported images are taken in the timezone set in your computer and two: the gpx might be incorrectly time coded (depending on what local time you actually shot the image).   The lightroom issue is unfortunately a long standing issue with timezone support in Lightroom. It is caused by the absence of any standard to record timezones in camera but terribly annoying for sure and the assumption that Lightroom makes is not necessarily bad in general but is terrible for anybody (like us both apparently) that travels a lot. Daylight savings time (or summer/winter time) complicates that even further. I constantly have to correct for timezones, summer/winter time and more as cameras are just not smart enough to deal with this correctly. They really should be recording time in the raw files in UTC format but no camera that I have does that. They all just put the time in in whatever you set in the clock. So had you imported the images while still in Italy, everything would be working fine (apart from the two hour error in the gpx file), but since you imported while in Britain, you got the timecode offset. ... View more

Looked at this and you are dealing with a time zone offset issue. If you dial in a 6 hour offset in the tracklog in Lightroom it tags correctly. I think that the timezone is not set correctly in the gpx track file: <!-- TZ: 7200 --> or the timezone is not set correctly in your camera. ... View more

I do this all the time with track logs created using Gaia GPS (excellent app unfortunately bought out by outside magazine so probably will not be excellent for much longer) and have never seen more than a few feet of inaccuracy simply caused by the accuracy of the GPS. What do these track logs look like? Are they perhaps far apart in time just sporadically taking points, or like normal track logs every 30 seconds or so. If far apart, the interpolation algorithm that is used will matter tremendously, whether it sticks to a coordinate in the track log that is closest in time (nearest neighbor interpolation) or does a linear interpolation between two track points straddling the image in time. If the track log is very sparse (a point only every 10 minutes for example), these two methods will give wildly different results. No clue what Lightroom does but I would be surprised if it wasn't an interpolation method. ... View more

When clicking the update button (the circling arrows in the upper right below the histogram), does it at least get fixed to where it should be? The cause is probably a version mismatch between your classic install and your editor's. ... View more

You probably need to update Topaz or reinstall it. It should work just fine ... View more

Thanks for checking. Was worth a try but unfortunately not the problem apparently ... View more

I don't have a similar machine to compare so not sure but that line does worry me that indeed the GPU is not playing at all consistent with your observations. This machine should be at least as fast as that M4 Pro you compare to. I would reinstall the GPU driver and disable any custom settings on the GPU you might have done. Make sure you use the studio driver from NVidia and not the gaming one. From the system listing above you probably have the very latest version installed but good to check. ... View more

At the risk of sounding pedantic but have you tried hitting the "I" key on your keyboard or doing a command-I. I have noticed that sometimes, the info overlay doesn't show even when it is checked in the dialog. Pressing I a few times will bring it back. ... View more

There is also this notice in the lower section:  GPUDeviceEnabled: false It looks like the GPU is getting disabled more deeply somehow.  ... View more

Check out Jeffrey friedls collection publisher plugin: https://regex.info/blog/lightroom-goodies/collection-publisher ... View more

You have a lot of third-party plugins installed. I would try disabling them all and seeing if it still does the slowdown. If that helps, reenable the plugins one-by-one until you get the slowdown again. You really should see zero difference in performance with the new denoise vs the old one but the denoise data is stored very differently in the catalog in the new version and any plgins that scan and work with the catalog data might pose an issue.  Otherwise a cause might be that you have some antivirus software installed (not really needed on Mac OS because of the built-in AV software and different security model) that constantly scans the catalog.  ... View more

That looks like a graphics card(GPU) problem. Make sure your GPU drivers (if you're on windows) are up to date by going to the manufacturer's website and downloading the latest drivers. That usually fixes these kind of issues except for some older graphics cards such as Radeon cards that have this issue. So please post the relevant part of the system info dialog (help menu) to see what card you have. It can also be a problem with the monitor color profile. ... View more

That sounds like a gpu driver issue as others noted. The GPU you have should be fine but driver might need to be updated.  ... View more

If that solution (moving all into a new catalog) worked you have a bloated original catalog file. You might simply need to check the integrity of the original catalog and to optimize it. Hold your option key while restarting classic and select the original catalog in the dialog you get and hit the checkbox to check and optimize. That might help.  if you go with this new catalog, relinking to the cloud might go just fine but it might also duplicate everything you have in the cloud. Hard to predict. ... View more

What gpu do you have in that computer? Lightroom nowadays is very dependent on having a strong gpu. It will run slow even on machines with a fast processor and lots of memory if the gpu is underpowered. This is especially true if you use any of the ai features. ... View more

If you hold down the option key when starting classic, you'll get a dialog where you can check the integrity of a catalog file. Might be worth trying. If none of that works you might need to recover from a catalog backup. If you have a really hard deadline, you can always just create a new empty catalog and do your work in there. ... View more

This happens if you have a mask defined or are using one of the adaptive profiles (which creates masks in the background). Just recalculating the ai masks (there is a little circular icon you should see near the histogram in Classic) should fix these ghosts.  ... View more

The behavior for raw+jpeg is set in the preferences. There is a setting to treat jpeg next to raw as separate. It is indeed possible that your catalog has both raws and JPEGs as separate images in the same catalog folder and your Lightroom settings are set to not treat them as separate upon import. This might indeed make synchronize think the files are missing because it sees them as if they are a single raw+jpeg pair. I have never tried this but yeah try changing the setting for raw+joeg. ... View more

As already mentioned, you are going to need a new computer to be able to run the current versions of Lightroom and Mac OS that will allow you to open those files unfortunately. It is possible to trick Mac computers to install newer Mac OS versions by using openCore Legacy Patcher which is probably much further than most people are willing to go as it is definitely an advanced hack. ... View more

You will lose the ability to denoise a dng image if it is a HDR merge, a panorama merge, or if it was exported using the lossy compression option. It is also possible that it originally was a raw image shot at reduced resolution in camera. That also creates a linearized raw file. If that later gets converted to dng, you would not be able to denoise that image. ... View more

Not sure what you mean the new tool works exactly like the old slider but now you can live change the amount of denoise instead of having to generate a new dng file. The slider is exactly the same. 50 means half the full effect, 100 means maximum effect. Just like it did before. Just no new file needs to generate. ... View more

try creating a new catalog and import a few images. See if that is still slow. It appears you have been upgrading this catalog since Lightroom version 5 so perhaps some problems slipped in. ... View more

it would make the slider incredibly slow to respond if they didn't store the denoise data as every time it would need to recreate it. The data it stores is a reduced representation of the raw data as seen by the ai. The cool thing is that doing it this way allows them to on the fly dial in different denoise levels. Secondly, when you turn on xmp backups, what Lightroom Classic does is store the exact same data in the xmp sidecar backup as it stores in the catalog files. So this also includes this fast denoise data. This is no different from all the AI masks, AI remove data, etc etc. that all gets stored in the xmp sidecar if you enable the auto xmp writing even if Lightroom or camera raw could easily regenerate those masks. This can make the xmp sidecars really big indeed. ... View more

Are you sure the xmp files don't get actually updated when you are stepping through? Finder can be extraordinarily sluggish with updating the metadata columns. It certainly seems like Lightroom is saving something seeing how long it takes to count down the number of saves left. Often you have to close and reopen a folder to see any updates.  Anyway, these are clearly bugs with the automatic xmp writing system. That has always been very buggy unfortunately.   ... View more

Normally the denoise result is put in the catalog only. It only gets put as a copy in the xmp when you have automatic xmp writing turned on. This data has to reside somewhere. In previous versions of Lightroom, a separate dng file would get created with the denoise data. In the new version, the denoise data that allows you to charge the amount of denoising after the fact is stored in the metadata in the catalog. Denoising this way unavoidably adds some megabytes that have to be somewhere. ... View more

The way to work is exactly the same as if Classic is the master. Classic simply ALWAYS works as if it is the master of the universe. SO when you want to occasionally use CLassic, know that it will ALWAYS download everything new from the cloud. So be prepared to always have a full copy of everything in the cloud in your Classic catalog if you go this way. There really are only two options when involving the cloud. One go full Lightroom Cloudy and never use Classic again. 2. use Classic as the master, import in Classic and sync smart previews or import in Cloudy on mobile or Desktop, and be prepared that everything always will get downloaded to Classic.  You really cannot use Classic just a bit. It won't work that way. ... View more