Plesk update/upgrade fails: The installation of the package ‘iiscompression’ failed with code 1603

Symptoms

Plesk update/upgrade fails with the following error message:

Installing packages
Upgrading Microsoft IIS Compression...
Failed to install 'C:ProgramDataPleskInstallercachepoolreleasePLESK-WIN_18.0.48_10183thirdparty-windows-x86_64iiscompression_amd64_1.0.6502.msi': Fatal error during installation. (Error code 1603)
Sub-action 'InstallMsiPackage' failed with error code: 1603(0x00000643)
Launching component and product checkers...
Downloading file pool/release/PLESK-WIN_18.0.48_10183/reportupdate.exe: 0%
Downloading file pool/release/PLESK-WIN_18.0.48_10183/reportupdate.exe: 100% was finished.

ERROR: The installation of the package 'iiscompression' failed with code 1603. (upgrade: Upgrading Microsoft IIS Compression...)
Not all packages were installed.
Visit https://support.plesk.com/ to search for a solution.
exit status 1

Cause

The cause is not clear. Most likely IIS service is holding the IIS Compression and preventing it from being uninstalled/reinstalled.

Resolution

1. Connect to the server via RDP

2. Start a command prompt as Administrator

3. Stop IIS service:

   Warning: Plesk and websites will be offline while IIS is stopped.

   C:> iisreset /stop

4. Manually install the package using the directory from the error message, e.g. C:ParallelsInstallercachepoolreleasePLESK-WIN_18.0.48_10183thirdparty-windows-x86_64iiscompression_amd64_1.0.6502.msi

5. Start IIS service:

   C:> iisreset /start

6. Start Plesk update again