Hi,
yes, this is a pain, the folder "__internal" is featured with a cap "__Internal" on some reps and Unity doesn't find the path properly,
so you need to shake it a bit, rename "__internal" to "test", wait for Unity to recompile and then rename it "__Internal" with a cap I, it should work then when you download the action again..
Sorry for the inconvenience... not sure how to fix this properly.
Bye,
Jean