This thread has shown up an unfortunate and unintended naming collision—looking at TBX v0.5.4.
In note “Publish single note to DEVONthink”, the code below declares a variable ‘linkPath’:
var linkPath(exportedString(l, "^path^"));
In 2018 that wasn’t problematic. But in v9.0.0, a new action operator linkPath(). I’m not sure how such a name collision is handled. But, even if the doc works, I’d suggest updating the TBX to use a variable with a non-clashing name. I avoid this by prefixing all my variable names with a ‘v’ which makes variable names immediately obvious. Of course, other naming methods are equally helpful - mine’s just one such.