Hi,
Ranorex Studio 8.1 has been released over a year ago, which means your maintenance period may be expired? Are you sure your company paid renewal fee? You see, once you buy Ranorex, there is one year maintenance period, during which you may receive free updates (both major and minor versions). After that period, you can no longer use newer versions, unless you pay for renewal.
On the other hand, I don't remember any license status check, behind the download link in email you mentioned? So it may be just a temporary problem at Ranorex side or maybe your FW/antivirus is simply blocking download links? Please try to contact Ranorex support via their support form, available here:
https://www.ranorex.com/support-query/