Renaming file(s) on the Finder is sometimes rejected while I download images…

I have a project where I give it a start date, an end date and an URL (special URL where I download images files from).

Unfortunately, because of errors (between other hazardous stuff), I have to manually add an index file to the already downloaded images files.

To avoid > 23,000 files in one macOS folder I set some folders and rename iage files to one folder while my application download fresh images into a different one.

The used hard disk is the boot disk, SSD. No HD connected.

What happens on a regular basis is… the just modified file name is… rejected (one here and there, never two or more in a row).

While I was downloading something else with Firefox, a large archive, I was renaming files. And, after a while I realized that… the renaming rejection bug is no more there. So, this is clearly a “bug” from the application built with Xojo 2015r1.

Unfortunately, I do not know what to do (beside stopping to rename files when the application download images), where to search (if the bug is mine).

Ideas ?

Last El Capitan version (up to date).

PS: I usually check this kind of troubles with the current Xojo version (2017r3 today), but since my troubles Xojo anti-piracy system are still there, I cannot (and do not want) to run Xojo (the IDE) while Internet is on.

The used code to save images files (gif / jpeg) is:

No taker ?

Are you trying to save more than one file per second, thus having a file name clash due to dates in the filename?

It could be, but no, this is not the case.

I had (minutes ago) to do that (my fault, I think *) for some strips, and must do that in Icon view (not list view) / macOS.

The rename part is rejected while I was typing - in Icon view -, (after I pressed the Return key in the List view).

BTW: on macOS, renaming a file using one already existing in that folder displays a dialog to inform the user about the name clash.

I was not able to get the image width (at develop time / before naming the file-saving the file), and so I used a generic value (900) while it can be 600, 900 or 1200.

The night was not so good, but something comes from “dark memory” late this morning:

this is an OS bug.

Apple’s engineers squashed this bug a bit (in list view), but it is still here (in El Capitan).

The bug appears (after long reflexion) when both conditions happens at the same time: a new file is saved by my application AND I press the Return key (after renaming the file).

The fact that it was nearly all the time the same suffixed file name (three possibles suffix exists in this case)is just a pure hazard (IMHO).

Sorry for the noise.