how to empty sandbox, when browser runs in sandbox?

I have firefox set to always run sandboxed.
If I empty sandbox, firefox cannot run afterwards.
How to empty sandbox without affecting browser?

I’m guessing you want to empty the sanbox contents while still having firefox open? Then I guess you could manually go into the VTRoot folder located at the root of your system partition. Though reset sandbox is when you are done using sandboxed apps or if you notice malware behavior and want to “clean” it out. e.g. a ransomware screen that has no close button.

even if I have already closed firefox. and then I reset sandbox, I run into a problem when I want to run firefox again.
The workaround I use is to delete the firefox autosandbox rule after resetting sandbox, and then make the firefox rule again.
But maybe there is an easier way to deal with this?

That sounds like a bug and should be reported, are you using the beta by chance? I haven’t experienced this problem.

yes, I am using the latest beta.

What Windows version are you using and is it x64 or x86? if running a x64 are you using the 64-bit version of firefox? And what other security software do you have installed that might cause issues. If you have the time I suggest creating a bug report here using the required format.

windows 10 x64 stable build
firefox 50.0.2 x64
I am running HitmanPro.Alert