How to fix error 0x80073701 when adding roles or features to Windows

Error code 0x80073701 translates to ERROR_SXS_ASSEMBLY_MISSING. This is sometimes encountered in Windows when you attempt to add a role or feature and Windows registry considers a specific package to be installed, yet the manifest is not present on the system. Here is how you can fix it.

1. Open the file C:\Windows\Logs\CBS\CBS.log (or CbsPersist_<date>.log)
2. Find the error code: 0x80073701
3. If you find a line with error code 0x80073701, note the name of the file.
4. Run PowerShell as Administrator.
5. Run ERROR_SXS_ASSEMBLY_MISSING.ps1
6. Enter the full path to log file noted above. If the log in question is the default CBS.log file, you can leave it blank. Press Enter.
7. If all works well, it should verify one or more packages’ state and say “Verification passed, Retry Enabled”.
8. Retry the role/feature installation again.

Example script usage:

PS C:> C:\temp\ERROR_ASSEMBLY_MISSING.ps1

Transcript started, output file is C:\Windows\system32\AssemblyMissingScript-20231004-1323-35.log
Please enter CBS file path (Default Path: c:\windows\logs\cbs\cbs.log): C:\Windows\Logs\CBS\CbsPersist_20231004033718.log

C:\Windows\Logs\CBS\CbsPersist_20231004033718.log
Checking resolving packages
Found following resolving packages
True
Mark this package absent Package_3817_for_KB4601383~31bf3856ad364e35~amd6410.0.1.7 True Mark this package absent Package_3819_for_KB4601383~31bf3856ad364e35~amd6410.0.1.7
Verifying package state
0 of Package_3817_for_KB4601383~31bf3856ad364e35~amd64~~10.0.1.7
0 of Package_3819_for_KB4601383~31bf3856ad364e35~amd64~~10.0.1.7

=========================================================================

Verification passed, Retry Enabled

=========================================================================
Transcript scopped, output file is C:\Windows\system32\AssemblyMissingScript-20231004-1323-35.log
Press Enter to continue…:

As I understand it, the script performs the following steps:

1. Examines the CBS.log file that is passed to it:
   • Verifies the log file contains a line with the text: ERROR_SXS_ASSEMBLY_MISSING
   • Collects the lines from the log that contain the text: Resolving Package:
   • Using the lines collected, extracts the full package name(s), such as: Package_3819_for_KB4601383~31bf3856ad364e35~amd64~~10.0.1.7
     • This is done by taking each line into a variable $packageLine, and then running this to split and select the package name and assign it to an array: $packageLine.Split(“:”).Trim().Split(‘,’).Trim() | Select-String “Package_”
2. Updates the registry as follows:
   • Looks at the following key: HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Component Based Servicing\Packages
   • Connects to the subkey matching the name of the package(s) identified in step 1c, and performs the following:
     • Takes ownership of the subkey.
     • Updates the subkey ACL to add FullControl permissions.
     • Sets the subkey value named CurrentState to DWORD data: 0
3. Verifies the registry changes in step 2 were completed.

Note: Script is linked below. Use at your own risk. No support or warranty is provided by me.