The F26 RPM for 5.1.30 in https://www.virtualbox.org/wiki/Linux_Downloads is named VirtualBox-5.1-5.1.30_118389_fedora26-1.x86_64.rpm. All earlier RPMs for F26 were labeled fedora25 (for example VirtualBox-5.1-5.1.28_117968_fedora25-1.x86_64.rpm). The version of 5.1.30 in http://download.virtualbox.org/virtualb ... fedora/26/ is still labeled fedora25, so after I installed manually from the download page, I am prompted to downgrade from VirtualBox-5.1-5.1.30_118389_fedora26-1.x86_64.rpm to VirtualBox-5.1-5.1.30_118389_fedora25-1.x86_64.rpm. Please fix the version in http://download.virtualbox.org/virtualb ... fedora/26/ . Thanks.
Edit: Confirmed that the files are actually different:
VirtualBox-5.1-5.1.30_118389_fedora25-1.x86_64.rpm: 71946974 bytes
VirtualBox-5.1-5.1.30_118389_fedora26-1.x86_64.rpm: 71898202 bytes
I believe that before 5.1.30, the Download page had a single download for both F25 and F26, labeled fedora25.
Issue with Fedora 26 repo and 5.1.30
Re: Issue with Fedora 26 repo and 5.1.30
This should be fixed now... the repo still had the symlink from 26 to 25 which should've been removed already with 5.1.28. Will take a while until it makes it into the public, but you can check yourself by looking at http://download.virtualbox.org/virtualbox/rpm/fedora/ - as soon as the directories 25 and 26 show up with different timestamps this should be sorted. The difference between the two packages is actually minimal, primarily it's about the supported python 3.x version.
Re: Issue with Fedora 26 repo and 5.1.30
Shortly after your post, the time on the 26/ dir was changed, and the files in it appear to be the correct ones labeled fedora26. Yet my package installer still wants to downgrade to the fedora25 version (and I've refreshed its metadata). Will keep checking.
Re: Issue with Fedora 26 repo and 5.1.30
Try again... depending on where you are on the planet it might need a bit more patience for the update to reach all CDN servers. Turned out that previously the repository data files were not created, and having only the rpms in place isn't enough.
Re: Issue with Fedora 26 repo and 5.1.30
Just checked again, and it's fixed. Thanks.