I would suggest you to double check the Update Manager
and update packages. Since RC3, the corresponding folder is located under:C:\Users\<your username>\AppData\Local\Itoo Software\RailClone Pro
If the issue persist, please try to "reset the Update Manager" by deleting the following registry key (using "regedit.exe"):HKEY_CURRENT_USER\SOFTWARE\Itoo Software\Update Manager\Packages
Alternatively, use the attached .reg (open the zip and double click the .reg file). Reinstalling the plug-in is highly recommendable too.