Cannot Upgrade S/W on Flex 6500

I have one of the original Flex 6500s. It is running SmartSDR v2.9.2 and works perfectly with my Dell PC and also works with the IOS SDR S/W. Every time I have tried to update the S/W to a newer version of SmartSDR I have gotten the same error (SmartSDR file transfer error. Please try again). Since the radio has always done everything I wanted it to I just skipped the upgrades. I would now like to install SmartSDR on my Surface LT and I only find SmartSDR v2.12.1 available on the site. When installing, I get the update radio window and the same file transfer errors I have gotten in the past. Is there a fix for the error or a S/W archive where I can just download the v2.9.2 S/W?