Yes, it has been a while! Been busy with life.
However, just fixed an issue on the new release of PowerBI Report Server - January 2019.
We use training videos on the report server to show the users how to use the dashboards; however, after the January release, I was restricted from uploading the file due to the error:
"Uploading or saving files with .mp4 extension is not allowed."
After a bit of digging around, I found this entry in the ConfigurationInfo table in the ReportServer database: AllowedResourceExtensionsForUpload
I simply added *.mp4 and now I am allowed to upload the videos again!
Hope that helps