Observability

SolarWinds Platform upgrade fails - Error 1620 on the MIBs (MIBsv2.msi) component due to a corrupt Windows Installer cache file

This article provides information about a SolarWinds Platform upgrade failure where the MIBs component (MIBsv2.msi) fails to install with MSI error 1620, even though the MIBs component is already at the same version. It describes the symptom, cause, and a validated workaround to complete the upgrade.

First published date

6/16/2026 6:42 PM

Last published date

6/16/2026 6:42 PM

Overview

During a SolarWinds Platform upgrade, the installer attempts to install the MIBs component (Observability-<version>-MIBsv2.msi). The installation fails because the Windows Installer cache file for the previously installed MIBs component (located at C:\WINDOWS\Installer\<random>.msi) is corrupt. Windows Installer cannot open the cached package, so it can neither upgrade nor uninstall the existing MIBs component, and the upgrade fails.

 

This occurs even when the installed MIBs component is already at the same version as the one being installed.

 

Sample messages that may be seen in the logs:

In the MIBs MSI log (MIBsv2.msi.log):

=== Logging started: <date> <time> ===
DEBUG: Error 2276:  Database: . Codepage 18404 not supported by the system.
1: 2276 2:  3: 18404
This installation package could not be opened. Contact the application vendor to verify that this is a valid Windows Installer package.
C:\WINDOWS\Installer\<random>.msi
MSI (s) (XX:XX) [<time>]: Product:  -- Installation failed.
MSI (s) (XX:XX) [<time>]: Windows Installer installed the product. ... Installation success or error status: 1620.

In the Administration service log (AdministrationService.Client.log):

INFO  ... MsiExecutor - Installing C:\ProgramData\SolarWinds\Installers\Observability-<version>-MIBsv2.msi ( REBOOT=ReallySuppress MSIFASTINSTALL=7) in version <version> (MSI version = <mibs-version>)
INFO  ... OipClient - Tracking event: ... InstallChain::Msi error code: 1620 - False - 0
ERROR ... MsiExecutor - Installer Exception. Error Record:  - Error Code: 1620

Key indicators:

  • MSI error 1620: "This installation package could not be opened."
  • Underlying MSI error 2276: "Codepage 18404 not supported by the system."
  • The failing component is the MIBs package (MIBsv2.msi).

Product section

Hybrid Cloud Observability

Cause

The Windows Installer cache file for the existing SolarWinds MIBs component (C:\WINDOWS\Installer\<random>.msi) is corrupt. Because the cached package cannot be opened, Windows Installer cannot remove or replace the existing MIBs component during the upgrade, resulting in error 1620.

This is a corrupt local installer-cache condition. The MD5 hash of the corrupt cached file does not match the known-good staged MSI, confirming the cache file itself is corrupt.

Resolution

The following steps restore the corrupt cache file from the known-good staged MSI, remove the orphaned MIBs registration, and allow the upgrade to complete. Run all commands in an elevated (Administrator) session.

1. Identify the installed MIBs product:

Get-WmiObject -Class Win32_Product | Where-Object { $_.Name -like "*MIB*" } | Select-Object Name, Version, IdentifyingNumber

2. Locate the cached MSI for the MIBs component:

Get-WmiObject -Class Win32_Product | Where-Object { $_.Name -like "*MIB*" } | Format-List LocalPackage, PackageName

Note the LocalPackage path (for example, C:\WINDOWS\Installer\<random>.msi).

3. Confirm the cached file is corrupt by comparing its hash to the known-good staged MSI:

Get-FileHash "C:\WINDOWS\Installer\<random>.msi" -Algorithm MD5
Get-FileHash "C:\ProgramData\SolarWinds\Installers\Observability-<version>-MIBsv2.msi" -Algorithm MD5

If the hashes do not match, the cached file is corrupt.

4. Replace the corrupt cache file with the known-good staged MSI:

Copy-Item "C:\ProgramData\SolarWinds\Installers\Observability-<version>-MIBsv2.msi" "C:\WINDOWS\Installer\<random>.msi" -Force

5. Uninstall the MIBs component using the restored cache file. Use the file-path form of the command (the product-code form may prompt for parameters and fail):

msiexec /x "C:\WINDOWS\Installer\<random>.msi" /l*v C:\mibs_uninstall.log REBOOT=ReallySuppress

6. Verify the MIBs component was removed:

Get-Content C:\mibs_uninstall.log | Select-Object -Last 50
Get-WmiObject -Class Win32_Product | Where-Object { $_.Name -like "*MIB*" }

Removal is successful when the log reports completion with return status 0 and the second command returns no results.

7. Re-run the SolarWinds Platform upgrade. With the orphaned MIBs registration removed, the MIBs component installs cleanly and the upgrade completes.