Weird looking paths get added to Windows 10 search index and break search

Question

I am using Windows 10 Pro (1709).

A few times in last weeks I have noticed that search from start menu wont find any files. Simply rebuilding the index did not fix this. Looking deeper into indexing settings I found that there was strange looking path being included in the index, one that I had not put there.

The included path looks like this:

csc://{S-1-5-21-773843817-2136397924-2028731201-1001}/

Mouse over this path bring up text saying that this path is not available and cannot be indexed.

Start of the path looks like protocol definition but I could find information about any csc protocol. The second part is SID of my user account. (I am only user on this computer and it is not connected to domain.)

Removing that path from indexing targets and rebulding the index has fixed this problem so far but I would like know

1) What is this path

2) Why does it get added to search indexing on its own

3) How can I prevent this from happening again and breaking my search

Answer 1

CSC stands for "Client Side Cache" which is used to hold Offline Files. These are local copies of files that exist on SMB shares like mapped network drives. By default, Windows indexes the CSC so that you can quickly find any network files that you've opened recently. The CSC index can become corrupt and put a full bork on indexing.

Solution:

1. Open registry editor (regedit.exe)
2. Goto HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Csc\Parameters
3. Add a new DWORD called FormatDatabase and set its value to 1
4. Reboot

5. Open Manage Offline Files

   • In Control Panel > Sync Center > Manage Offline Files

6. Disable Offline Files

7. Reboot

8. Open Indexing Options

   • In Control Panel

9. Click Modify

10. Remove all "csc://" entries and anything else you don't need an index of
11. Click Advanced
12. Delete and rebuild index with the Rebuild button