I have a 128GB Macbook Air and a 256GB Mac Mini. I'm trying to run both with non-critical applications (my Mac gaming library) stored on an external drive. This worked in Sierra, but has had a few idiosyncrasies in High Sierra and Mojave. For example, 3rd party applications like Guild Wars 2 must be run at least once on the internal drive because I can't find any way to click past the 'are you sure you want to run an application downloaded from the internet' warning if first installed on an external drive. Worse, other applications like Kerbel Space Program will crash on execution if installed on a non-boot drive. Does anyone know what security feature is causing this and if it can be safely disabled?