Is it possible to itterate all Lists in SharePoint to find out which ones use a custom Lookup field?
I have an application which is currently failing because the custom Lookup field was pointing to a redundant URL which was removed.
It is not clear from your question what kind of solution you are looking. My answer is code based and tested on SP 2010 platform.
So here is c# code (link):
or you can use something similar using PowerShell:
So I am not iterating lists but instead I am using