Packages lack or bad download URLs
Tried with F-Droid app v0.102 on Android 4.2.2 (CM10.1) and F-Droid v0.102.3 on Android 5.1.1 (CM 12.1). Some applications are not installable (default~last version) because of package download fails. Error message seems to report duplicated address about tried URL, and might be ocurring when having both "F-Droid" and "F-Droid Archive" repositories are enabled.
Eg: 24game v0.5 -> https://f-droid.org.... https://f-droid.org....