Summary

When attempting to run the Jira installer .exe file on a Windows Server 2012 or higher server, the installer may fail to run with a warning message:

Another possibility is that the installer may appear to run but pop up messages during the installation note that there were issues copy DLLs to the bin directory.

Environment

Microsoft Windows Server 2012 and higher

Diagnosis

This can manifest itself in a few different ways depending on the version of Windows being utilized.  

1. The installer will not run at all.  Attempting to run the installer as an Administrator or standard user results in the Microsoft Defender error referenced above.  
2. On some versions of Windows, the installer may appear to execute when running as an Administrator, however you will see messages noting that certain operations like registry updates or moving/writing of DLLs to specific directories failed.  

Cause

Windows Server 2012 and higher machines can block files that deemed to be "potentially dangerous" when downloaded.  This often includes .exe, .dll or .msi files.  Since the Jira installer is a .exe file, often times Windows will block the installer download which can lead the installer to not run properly when executed.

Solution

Unblock the installer and make sure to execute it as an Administrator as described below: 

1. Right click on the Jira installer .exe file and select Properties 
2. At the bottom of the window select the 'Unblock' checkbox and choose Apply

Once the file is unblocked, run the installer executable as an Administrator.