When our app downloads samples and files for installation, it first stores the file in your device's internal space, even if you have an external SSD connected. Unfortunately, this process is necessary, because there is not enough memory to download and extract simultaneously. This is why it may seem you don't have enough memory, because you need enough system/internal space on your device for the extraction process to happen. This is why there are specs for Internal Space Needed and for Installed Size on the drive. You have enough external SSD space, but you don't have enough internal drive space to do the processing.