SQL SERVER – Unable to Add Node – Could not find subkey System \ CurrentControlSet \ Services \ MSSQLFDLauncher. Error code 0x851B0001

This was an interesting scenario I encountered when configuring one of the clusters. I had finished installing SQL Server on Node1 and had started running ADD NODE on Node2. We got this error in the setup wizard before reaching the Service Account Password page.

SQL Server Setup has encountered the following error:
Could not find subkey System\CurrentControlSet\Services\MSSQLFDLauncher
Error code 0x851B0001.

I searched on the internet and there were various users facing same error. Most of them didn’t share the solution and those solutions, which were available didn’t work for me. In this blog, we would learn how to fix error “could not find subkey” with code 0x851B0001

It is important to note that actual add node installation didn’t start yet and we were in the wizard. We got this error in the setup wizard just before the Service Account Password page.


Based on my setup experience, I can tell that during the ADD Node procedure, SQL Server setup performs a remote registry query to get the details of the configurations which were set in Node 1. Looks like the setup expected this key to be present there, but unfortunately, it did not find one and thus gave the error. The service and key MSSQLFDLauncher is for SQL Server Full-Text Search. We went to Node 1 and found Full-Text Search was not installed!

Now customer told us an interesting thing. They did not see Full-Text Search option while installing on the first node. So, we decided to remove SQL Server from Node 1 and try to re-install.  While re-installing, on the Features Page we were not able to see the Full-Text Search option.


After a bit of testing on my lab server, I was able to reproduce the issue! We will not see a feature listed on the Features Page if the respective MSI file is missing from the Setup Media. Full-Text Search using the MSI called sql_fulltext.msi and is present in the setup path MediaRoot\x64\Setup. I was not able to see the sql_fulltext.msi file in the client’s setup media. I was suspecting other files to be missing too so we extracted a fresh copy of the setup media (from new downloaded ISO) and then ran the “New Failover Cluster” setup. This time, we were able to see Full-Text Search option. Let us learn how to fix the error related to unable to add node.

We selected the components and went further with the setup. Setup completed fine on the first Node. Then we used the same “good” media to run Add Node and that too completed successfully.

Have you encountered such issue? Was it something other than setup media issue? Please share via comments.

Reference: Pinal Dave (https://blog.sqlauthority.com)

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