The primary hurdle for a user searching for "GarageBand 10.1.6 download" is the App Store’s default behavior. If a user on El Capitan opens the App Store and searches for GarageBand, they are typically offered the latest version compatible with their device. However, due to server-side changes and application aggregation, this process can sometimes fail, or the user may be prompted to download a version that is incompatible with their specific hardware limitations.