Apparently, a pretty big bug went unnoticed due to my inability to properly test 64-bit RD Tabs! (The good news is that I have access to a 64-bit machine now, so these should be less in the future.)

RD Tabs uninstaller (which fires when you upgrade RD Tabs too) launches a program called regtsax.exe which performs a bunch of clean-up operations. It was recompiled 64-bit, like everything else for the 64-bit versions, but the MSI installer service can't seem to reference this 64-bit module, for whatever reason.

So I recompiled it to "any CPU" instead of 64-bit and this fixes the issue.

The original version of 2.1.2 alpha contains this problem, but I have since updated the 2.1.2 installer so that it is fixed.

If you cannot uninstall RDTabs, download the following zip file below, extract the updated regtsax.exe and copy it into the Program Files\Avian Waves\RD Tabs 64 folder. Now try uninstalling. This should fix it.

http://www.avianwaves.co...Tools/RDTabs/regtsax.zip 

Sorry about that!