It seems you can't install the 1.1 beta if you don't have the original game installed. Here is a solution I found.

1. Go to the Impulse Settings and disable "show pre-release version". Restart Impulse.

2. Install Elemental (it's the old version). Switch "show pre-realase versions" on again. Restart Impulse.

3. Now you can install the (beta 1.1) patch

It seems you can't install the 1.1 beta if you don't have the original game installed. Here is a solution I found.

1. Go to the Impulse Settings and disable "show pre-release version". Restart Impulse.

2. Install Elemental (it's the old version). Switch "show pre-realase versions" on again. Restart Impulse.

3. Now you can install the (beta 1.1) patch

(sorry, was posted in the support section before)