This article applies to other Redgate products as well.
If your upgrade installation is stuck at 99% and then fails after few minutes, there is usually an issue with Redgate Client service upgrade.
Please go to
C:\Program Files (x86)\Common Files\Red Gate\Shared Client, delete any files named
.rgupdate_bad_x.x.x.xxxx and try again.
If the problem persists, please click the Redgate logo in the top left corner of the installation UI and log a ticket with Support.