Try it after each of these
1. Reboot
2. Reinstall "As Administrator", i.e. right click on the Setup.exe and select Run As Administrator; when given the option, select REPAIR; go ahead and reboot
3. Same as step #2, except Disable your Antivirus software before running the Setup again (unplug from the Internet if your IT Nazis don't like that idea)
4. Rename your DmDComm.rst file in C:\Users\Public\Documents\Do-more\Designer2_6\Bin. If this fixes it, let us know and email that file to support at hosteng.com