Add-on "Empty Cache Button" not working when boxed

[000]

Sandboxie 5.22, Waterfox 64-bit v56.0.1 (latest), on W764.

The Empty Cache Button is a simple add-on that does what it says. Click it and it empties your cache. When it is successful a notice pops up. It works fine when the browser is not sandboxed, but fails when running in SBIE. No notice pops up and cache is not cleared.

Any guidance on how I can troubleshoot this issue? (I would use the other popular cache cleaner , Clear Cache, but it has a bug where the toolbar icon for it becomes GIANT when installed on some machines [like mine], so can't even test it.)

TIA

EDIT: Confirmed with Cashe Viewer it IS actually cleaning the cache... the popup that lets you know it did that just isn't working when Sandboxed. Would still like to fix this if possible.

[Barb@Invincea]

Hello 000,

I am not able to reproduce the issue.

Please try a new Sandbox with default settings and let me know if the problem persists.
Are you using any antivirus software?

Regards,
Barb.-

[000]

Thanks for your reply. No AV. The add-on also does this in FF v56.0.1 (same as the Waterfox version I am using), when boxed only. Will have to revisit this later ... having to deal with router problems at the mo' that will occupy the next couple weeks. Will come back when I can. (It's a small thing anyway!)