Unable to delete images from 7.2 Lightroom Classic

[photofan731]

Using MacOS High Sierra version 10.13.4

I am using 7.2 Lightroom Classic ( not upgrading to 7.3 because of so many problems with it)

All has been working ok until yesterday when I am unable to delete images from Classic

This prompt keeps appearing :

AN INTERNAL ERROR HAS OCCURRED

?:0 attempt to index field 'rootFile' (a nil value)

Please help

[Rob_Cullen]

Some more info?

Are you 'Removing' the photos from the catalog or 'Deleting from Disk' ?

Are you currently viewing in the Library Grid view when you select photos and 'delete'?

Are you selecting photos on the filmstrip to 'delete'?

Are you trying to delete from the Develop module?

Do any of the photos show the "missing" icon [ ! ] on the thumbnail borders?

Are the originals on an external drive? and it is Connected?

[photofan731]

Thanks for reply

The system seems to have righted itself today,  would be good to know why it happened

In answer to your questions, in case it happens again:

1 Deleting from disk

2 Viewing in Library Grid

3 Not selecting from filmstrip

4 Yes 'some' had ! icons

5. Originals not on external drive

Thanks

[Rob_Cullen]

This cryptic error   [?:0 attempt to index field 'rootFile' (a nil value)]  appears for many people and rarely do we see any answers.

My simple understanding is that Lightroom is trying to do something that the operating system has no knowledge about.

Like 'Deleting an image' that does not exist (a "missing" image), but normally Lr would just ask to "Remove" the preview.

One known reason for the error in the Lr Export dialog is to have an empty field in Post Processing: [After Export] (it should show "Do Nothing" or another option, but not be blank.)

I hope it is permanently sorted for you.