Stacking while creating previews, get internal error

[DClark064]

If I am creating 1:1 previews for a large number of files (e.g. 2714), and try to auto-stack the same set of images based on time interval (e.g. 2 sec), I get the following error,

This error happens frequently.  If I wait until the previews are completed and perform the same stacking operation, it works without error.

I am using version 12.4 of LRC,

[Rikk Flohr: Photography]

I am not able to replicate this failure on Win 10, LrC 12.4 

[DClark064]

I experience the error often.  Once I get the error, I can try repeatedly and the error persists.  The only way I can clear it is to change to another folder, then return to the "previous import" folder.  Then it works without giving the error.