I had what seems to be the same issue, and was able to fix it. it seems that there is an older (?) version of Javascript running in Chrome.
I had to go through the epm_advanced.js, epm_global.js and epm_???.js and change all the
function functionname( parameter = defaultvalue)
{ ...
}
lines to
function functionname( parameter )
{
parameter = typeof parameter !== "undefined"? parameter : defaultvalue;
...
}
I'm not quite sure how to update the code in the repository (GIT?), but I'm sure that there are a few smart cookies that can do it.