Duplicate File Finder (Checksum project-Stage 3)

While the Checksum Project Stage 2 is not 100% complete yet, I consider it stable enough (thanks to help from LJMetzger) to move onto the next stage - a Duplicate File Finder.

See v3.01 attached.

On the tab marked Stage3 there are two buttons.

The first button is a shortcut to the File/Folder Lister from Stage 2. On the Form that appears, select the Custom Search option, Folders = No, and Files = Yes. (Up to you whether you choose to filter the file extensions or not).
It should produce a workbook that contains a range of file paths (FullName) in Column A.

The second button prompts for a workbook to import. Choose the workbook that you created using button 1. It should output a workbook containing a list of the duplicate files and their respective checksums.

1. The duplicate code is something I threw together. I'd appreciate suggestions on how to improve it. (It's in Module1)
2. The tool needs testing. I'd be grateful if anyone could point out any unhandled errors and how to trigger them. (Apart from the ones I'm aware of - see comments in sub CalculateFileCRC32Checksum_ListImport in module t_ref_CRC_Checksum_140403 )

UPDATES: I don't have time to clean the current version for uploading but just a quick note:
* There is a minor error in the Duplicate module. It should set variant to vbnull not erase variant as it currently appears.
* Also I have rethought how Stage 3 will work. It is stupid to checksum all the files all over again just to find the duplicates. Instead the current (unreleased) version accepts a file list with checksums (from Stage 2 Step 2) and then checks for duplicates on this imported list. Much faster.
* I want to clear Stage3 fast so I can move onto future stages...

So I realize this was posted a little while ago, but just to let you know, I'm working on making my own duplicate file finder. Mine is very raw right now, but if you want to share ideas, let me know.

Originally Posted by k64

So I realize this was posted a little while ago, but just to let you know, I'm working on making my own duplicate file finder. Mine is very raw right now, but if you want to share ideas, let me know.

I've sent you a PM