Not enough disk space
By default, the Contrail app downloads files onto the C drive before relocating them to your Community folder, Contrail Library, or other custom location. This happens for all downloads, including when the final location is on another disk.
Therefore, there are occasions when a download will fail because there is not enough space on the C drive, even when you have sufficient space on a second drive. The temporary space required is for the download itself plus the extracted files, for example the FA50 v1.0.4 requires 3.93GB of temporary disk space (1.58GB download and 2.35GB extraction).
Customise Contrail app settings
When it is not possible to make more C drive space available, it may be more appropriate to change the Download Folder location. To do this, go to the app Settings, on the General page scroll down halfway and locate the section labelled "Download Folders". Edit the "Temporary Download Folder" location to a new path, for example D:\Downloads. Restart the Contrail app to ensure that changes have taken effect.
Similarly, products that use standalone installers will be downloaded to the Windows user profile default Download folder that is located on the C drive. If you need to change this due to space issues on the C drive, edit the "Download Folder for Standalone Installers" and restart the Contrail app.