A DLL required for this install to complete could not be run

The solution is turn off your antivirus software during the installation as it can interfere with the installion process. This can be seen in the installation logs when running in verbose mode:

MSI (c) (94:30) [15:25:40:078]: Note: 1: 1723 2: CA_VALIDATE_LICENSE 3: ValidateLicense 4: C:\Users\SVC_SP~1\AppData\Local\Temp\2\MSI4361.tmp
Error 1723. There is a problem with this Windows Installer package. A DLL required for this install to complete could not be run. Contact your support personnel or package vendor.  Action CA_VALIDATE_LICENSE, entry: ValidateLicense, library: C:\Users\XXXXX\AppData\Local\Temp\2\MSI4361.tmp
MSI (c) (94:30) [15:25:43:791]: Product: SpiraTeam -- Error 1723. There is a problem with this Windows Installer package. A DLL required for this install to complete could not be run. Contact your support personnel or package vendor.  Action CA_VALIDATE_LICENSE, entry: ValidateLicense, library: C:\Users\XXXXXX\AppData\Local\Temp\2\MSI4361.tmp

In the example above (from a real customer), Symantec antivirus was locking the Local\Temp folder preventing the installer from accessing it.