In the past, I used to upload a new preview.png file to the theme in order to have the actual preview of a custom file.
In the 3.X-LTS version, when I do that the preview is not stored nor it is changed.
What shall I do to obtain the desired result?
TYA
Rita

indeed, now i see it has been changed. Weird.

You can't delete and upload preview.png ?

I cannot delete it because it does not appear in the file list.
I can upload mine but sometimes it updates it, sometimes not :side:

ritapas wrote: …
I can upload mine but sometimes it updates it, sometimes not :side:

Try to save custom.css file without update anything : this reset the asset url then : new preview is OK;

I think,
Denis

Or, if you have permissions, Configuration --> Global settings --> General--> Reset assets.

This reset ALL assets : admin + theme, with previous way : it update only theme asset

This reset ALL assets : admin + theme, with previous way : it update only theme asset

Yes, absolutely, but is that a problem.