Sharepoint Search Error 0FF1CE15-013A-0000-0000-000000000000 -Error loading type library/DLL.

I was setting up the sharepoint 2013 server and configured the sharepoint search in one of the app server(1 WFE, 1 APP and SQL server)

Everything was working as  expected, but last Sunday our infrastructure team has done windows update in APP server and SQL server(it seems to be other update as well).

After that there was strange behavior in the farm, like while running the jobs it was throwing access denied error, health usage report etc. So we asked infra team to revert the APP server snapshot to before update installed.

They have reverted the snap shot of the server and once they hand over the server, I checked 
the all the service application which we configured earlier, and Search service application was crashed due to server update happened in the APP server where search is configured and I was getting below error when I open the search service.

The Execute method of job definition Microsoft.SharePoint.Administration.SPServiceInstanceJobDefinition (ID a41c8bc6-6ee7-4039-b171-277686fc0b96) threw an exception. More information is included below.  Unable to cast COM object of type 'Microsoft.Office.Server.Search.Administration.MSSITLB.CGatheringManagerClass' to interface type 'Microsoft.Office.Server.Search.Administration.MSSITLB.IGatherManagerAdmin3'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{0FF1CE15-013A-0000-0000-000000000000}' failed due to the following error: Error loading type library/DLL. (Exception from HRESULT: 0x80029C4A (TYPE_E_CANTLOADLIBRARY))."

I thought my search service got screwed up and I need to create it from scratch. But I don't want to do that since everything was working as expected, so I just wanted to deep dive into the issue with ULS Log, Event viewer.

There was one clue was available in the error message i.e, 0FF1CE15-013A-0000-0000-000000000000

When I just saw this id, I assumed its  some thing related to Registry entry, either its having issue while accessing the Registry key or key might be corrupted(I was under assumption that whole registry got corrupted, luckily that was not the case)

Then I opened the Registry 

1) windows + run, type regedit it will open registry application(Make sure you open the registry with admin access else you wont be able to open)

2) Search for this specific key in the registry - Note here flower brackets are very important while searching else search return multiple value

3) This will be located under HKEY_CLASSES_ROOT\Interface folder

4) There will be 3 folder under this as like below

Above pictures shows the path of the key.

5) Here you need to select {0FF1CE15-0001-11B0-0000-000000000000} again curly braces are important and search under the registry folder HKEY_CLASSES_ROOT\TypeLib\

Please follow the path as depicted in the below screen shot.

As  we can see here its having the value "C:\PROGRA~1\MI95D8~1\15.0\Bin\mssrch.dll\1" which we can say its corrupted or its not having the proper location path.

This key value we need to change it to "C:\Program Files\Microsoft Office Servers\15.0\Bin\mssrch.dll\1" and save the entry.

Couple of notes:

1) These changes needs to be done in the server where search is configured, in my case I have done it in app server

2) After registry changes its recommended to restart the machine, please plan for that

3) After this registry changes search service  application will loose all its crawl history, need to run full crawl(basically search will not be in working condition, so we need to run full crawl)

4) In my case I have not created new search service application, existing application worked without any issue.

5) Query processing component will throw error if we search for items, in that time its required to start below services

• SharePoint Server Search
• SharePoint Search Host Controller
• IIS  Reset in all servers(Optional)