Value cannot be null. (specific string in specific path)

It will be in the folder where X1 keeps its index.

In my case it is here:

E:\Data\X1\Search 8\X1 Search\logs

But I have moved the index so for most people try:

C:\Users\{username}\AppData\Local\X1 Search\logs%userdata%

Or

%LOCALAPPDATA%\X1 Search\logs

Paste that into the location slot in Windows Explorer and see where it takes you.

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