[#] dummyparam.exe [#] and "Platform version '67.0.4' is not compatible with" errors

<Apologies if this is a known issue; I couldn't find stuff about it on the Forum>

When I load FFox in Sandboxie, I've been getting an error message, "Windows cannot find 'dummyparam.exe' Make sure you typed the name correctly, and then try again." I'm not sure if this is a FFox or Sandboxie error. 

When I OK past this dialog, FFox loads OK in the Sandbox.

However, when I click a link on Outlook, the URL doesn't load in FFox; instead I get an XULRunner error, 

Error: Platform version '67.0.4' is not compatible with
minVersion >= 67.0.1
maxVersion <= 67.0.1

I OK past that, and the page doesn't load. (I've had this since 67.0.2, I think, and I'm tired of the work-around below; I was hoping something would just fix itself over time ;-)

I can fix this problem by closing FFox, deleting the contents of the Sandbox, and starting over again. I don't get the dummyparam.exe error when I load FFox, or the XULRunner error when I click on a link in Outlook. Trouble is, it comes back every time I wake the machine from Hibernate.

I'm running Sandboxie 5.30 (64-bit) on Windows 10 Pro, version 10.0.17134 Build 17134; Firefox 67.0.1.