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1 Message


90 Points

Mon, Oct 3, 2016 9:24 PM

Lightroom: Metadata write errors

Hello all, 

Having constant issues with both Mac Lightroom 5 and Lightroom CC (2015.7) being unable to write metadata to sidecar XMP for my RAW files. I will sync my files, then Command-S to make sure all changes have been saved, before exporting. 

Preferences are set to “Automatically write changes into XMP”. Files are on a networked server. Permissions on folders are always correct (Read and Write), however when Lightroom writes XMP, I get the following error message, usually with random files, but not all: “Could not write metadata. Unknown file I/O error.”  If I sync the metadata (on the same files) using Bridge (using copy and paste), I get no errors. I don’t want to use Bridge, but that does show me the problem is linked to LR.

Was previously using Lightroom 5, and read that the error was a common LR5 issue, so initially went back to Lightroom 4. LR4 worked! Did not have the issue using LR4, but realized to my horror, after exporting multiple files, that all the edits I made in LR5 were incompatible with LR4 (for example, clone and heal tools were completely off their marks). Aargh! My fault for not checking backward compatibility. So, finally gave in to the cloud subscription thing (Lightroom CC (2015.7). But, issue is no better. Any suggestions greatly appreciated!





1.7K Messages


32.4K Points

4 years ago

Since this is a network drive, which often runs some sort of indexing/thumbnailing process in the background that could be interfering with Lr's metadata process. Avoid having your Windows explorer opening one of the folders. What types of image files that you are typically working with JPEG, TIF or DNG?

Principal Scientist, Adobe Lightroom

1 Message


62 Points

4 years ago

I have this same issue. Using Lightroom CC, working on iMac 27in late 2013 model running Sierra. I have been having this issue for months. Doesn't matter if I update Lightroom. Always an issue. Drives me NUTS. I have had a couple troubleshooting chats with Adobe and let them take over my computer. No answers have been found. Today, when the typical unsaved metadata symbol popped up, I told it to save. I then got a new error message. This is also a brand new catalogue. Thought that would help. No dice.
Exception Name: LuaRunException

Description: performCommandDesc could not perform command ag.library.file.writeSelectedXMPSidecars (Command was disabled.). 
User Info: {
    LuaErrorCode = 2;

0   CoreFoundation                      0x00007fffb359f52b __exceptionPreprocess + 171
1   libobjc.A.dylib                     0x00007fffc7c77cad objc_exception_throw + 48
2   CoreFoundation                      0x00007fffb359f479 -[NSException raise] + 9
3   AgKernel                            0x000000010750fe17 AgTransitQueue_enqueueToQueue + 3946
4   AgKernel                            0x0000000107513adb AgExceptions_setThrowHook + 230
5   AgKernel                            0x00000001074f76f8 lua_gethalts + 524
6   AgKernel                            0x00000001074f03d5 lua_error + 9
7   AgSubstrate                         0x0000000107630a4c AgLuaGlobalFunctions_init + 986
8   AgKernel                            0x00000001074f7e15 lua_gethalts + 2345
9   AgKernel                            0x00000001075065bb luaopen_table + 7593
10  AgKernel                            0x00000001074f80e1 lua_gethalts + 3061
11  AgKernel                            0x00000001074f00f1 lua_call + 37
12  AgSubstrate                         0x0000000107630ae3 AgLuaGlobalFunctions_init + 1137
13  AgKernel                            0x00000001074f7e15 lua_gethalts + 2345
14  AgKernel                            0x00000001075065bb luaopen_table + 7593
15  AgKernel                            0x00000001074f80e1 lua_gethalts + 3061
16  AgKernel                            0x00000001074f00f1 lua_call + 37
17  AgUI                                0x000000010755ce00 reorderChildWindows + 21880
18  AgUI                                0x000000010755de17 reorderChildWindows + 25999
19  AgUI                                0x000000010755e360 reorderChildWindows + 27352
20  AppKit                              0x00007fffb1a1f73d -[NSWindow(NSEventRouting) _handleMouseDownEvent:isDelayedEvent:] + 6341
21  AppKit                              0x00007fffb1a1bf8c -[NSWindow(NSEventRouting) _reallySendEvent:isDelayedEvent:] + 1942
22  AppKit                              0x00007fffb1a1b42a -[NSWindow(NSEventRouting) sendEvent:] + 541
23  AppKit                              0x00007fffb18bbbf5 -[NSApplication(NSEvent) sendEvent:] + 1145
24  AgUI                                0x00000001075acec4 AgColorUtils_sampleScreen_L + 6491
25  AppKit                              0x00007fffb11a2009 -[NSApplication run] + 1002
26  AppKit                              0x00007fffb116ca8a NSApplicationMain + 1237
27  Adobe Lightroom                     0x0000000107331b97 main + 1095
28  libdyld.dylib                       0x00007fffc8555255 start + 1

50 Messages


878 Points

4 years ago

I've had such an issue ever since at least LR5.  (I just can't remember if it was in LR4, but I thought it was.)  I had my photos on an internal drive, but I referenced them using a network share - in order to force LR to use the smart previews, due to speed.  However, now that LR finally has a preference setting for this, I just now have finally switched everything over to reference from the actual path, using the 'update folder location' in the right-click menu.  I'll see if it fixes the issue.

However here, I have never gotten an error message...  After saving metadata, it will just reshow the badge gain - or in the smart collection I use for it, it will disappear for a second, then reappear.

One thing I have done to fix these lately (discovered about a couple weeks ago) was to delete all snapshots and reset the image - and just start over.  That fixes it here.  So I'm thinking it must be some errant develop instruction that might be causing this.