The Bilateral blur has a bug whereby when the tolerance is set to zero, the whole image disappears (becomes transparent). This looks something like a divide-by-zero issue.
This bug has now been transferred to 1.10 Frequency Separation in the Bilateral tolerance slider.
Also, using straight Bilateral blur lets me knock out fine detail such as jpg artefacts, while the Bilateral in the Frequency Separation seems much weaker in this.