VEC Error - Action could not be applied due to missing or invalid mbox name

[NeelabhParmar]

Hi Everyone,

While trying to create an A/B test, I am trying for layout test for contents on page, by resizing container on one of the container and moving other using 'Layout' option. However any change gives me an error on modification pane as - 'Action could not be applied due to missing or invalid mbox name'.

Also I tried to go ahead and save the experience [even with error] and then test it using QA URL but just the default experience and not the test version.

Can you please help me to find the cause behind this error and fix it.

Thanks,