Hey Gang,
I have successfully downloaded the seven (the_grand_3.1.1_full) files for installation on a Win 7 notebook. During installation, I received the ‘checksum error’ message when attempting to extract from part2.rar file onwards.
Needless to say the installation failed.
I have attempted to download the seven files again from another computer/network but had the same problem. Are the files corrupted?
Pls advice. Thanks.
Had it figured out…
Just kept re-downloading the files until I had a ‘clean’ copy.
That was like after 3-4 attempts over 3 days!!
You can try Tools-> Repair as it work better if you have parity/recovery section (when generating the RAR file). However, it is very difficult to recover the corrupted file because checkdum are used to notify when something is corrupted and it does not really help to recover data.
Have a look at this – How to Fix Checksum Error in RAR File
Hope this might help you.
Hi
Did the download over the weekend - same issue as yours.
Just in between (I think file 5.rar…?) the extraction of the files the message appears.
Will download the *.RAR files ones more with a faster download line - hope this will help.
Thanks for your report, that there is hope, if the download is made several times 
Update 19.02.2016
OK. After re-downloading three of the seven files several times - finally I could install and operate the VST instrument - sounds really good - after long loading times. So far so good 
Cheers
FWIW - I got checksum errors a couple times (annoying)… so I simply took the missing .vstsound files from the MAC download… located, after install, in ~Library/Application Support/Steinberg/Content/The Grand 3/VST Sound.
I can’t remember if the files are visible prior to install (once you mount the .dmg), but my guess is they are…
This, of course, requires that you have a MAC.