Errors in running OS8.1.3 x64 server installer

[Mayada Al-Kishtini]

Hello $all,

I'm installing OS server version 8.1.3 x64 on a Windows server 2008R2/ 64bit -- using Omnis-App-Server-8.1.3-x64.exe installer file.
I have used this installer on the same version of windows more than 20 times so far with no issues. This time I'm getting an error when I try to run the installer (run as admin), the error says something like" error in copying files from packaged archive <path to the installer>  to C:\Users\DBSUPP~1.FI\AppData\Local\Temp\OS8.1.3SVR\Omnis-App-Server-8.1.3-Launcher-x64.exe..I have to click abort to the process to stop this error msg.

When I go to "C:\Users\DBSUPP~1.FI\AppData\Local\Temp" I see a file created called " bitrock_installer.txt", which has these log records:

Log started 01/29/2018 at 12:18:10
Preferred installation mode : win32
Trying to init installer in mode win32
Mode win32 successfully initialized
Executing cmd /c  "C:\Users\DBSUPP~1.FI\AppData\Local\Temp\OS8.1.3SVR\Omnis-App-Server-8.1.3-Launcher-x64.exe" --program "L:\DBDATA\DP_PRO~1\Server8\Omnis-App-Server-8.1.3-x64.exe" --userfilter "C:\Users\db.support.fi" --user_startmenu_path "\\HOST-GW01\tsprofiles$\db.support.fi\Start Menu\Programs" --user_desktop_path "\\<serevr anme>\tsprofiles$\<my user account>\Desktop" --local_user "C:\Users\<my user account>\AppData\Local" --temp_folder "Temp\OS8.1.3SVR" --isAdmin 1 --mode win32 --installdir "" --installscope user --serialno "" --adminaccount "" --adminpassword "" --showProg normal --projectDataFilename Omnis-App-Server-8.1.3-Data-x64.exe --instAppData 1 --editionAppend "SVR"
Script exit code: 0


My question, what makes this installer think that I need to run it in "mode win32"?
Anyone has seen this error before?

Thank you,
Mayada