Those are the hash codes for the GWX 2.0 parts which you downloaded.
These codes allow you to check to see if the file that you downloaded is still in it's original (compiled) state. Whenever you download files via the internet, there is always a chance that the file will become corrupted and thus the MD5 hash codes will not match up. This is purely a check on the downloaded files and will not cause the installer error report you have posted above.
The installer report which is part of GWX 2.0's installation process is created when the installer verifies certain aspects of your SH3 1.4b installation. In other words, it checks that certain files are the correct size based upon a 'clean/unmodded' version of the same file, also if any mods are still installed & activated (this can be individual mods or SH3Commander). The bottom line is that your supposedly 'clean/unmodded' installation which you want to add GWX 2 to, is not clean or unaltered.
Now, as previously stated, you may be able to load & play a patrol or campaign BUT you will more than likely experience game problem (probably in your best ever patrol) later on. It's advisable to get GWX2 installed correctly.
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