This typically occurs when the .net framework hasn't been installed or software installation failure.
First try uninstall the A2D2 software remember to use the windows add/remove programs then delete the installation directory
Then reinstall the software into a different directory. This helps reduce any misconfiguration issues from reoccuring.
If the issue still exists you can try a different version (version 10.5.5 will install the correct .net) or you can download and install the missing version as well.
Typically the correct version of the .net is automatically downloaded by windows when installing and running the A2D2 software the 1st time.
This section is for A2D2 Software Error Codes and general troubelshooting. (It will be continually updated)