This error happens because some macros and values are stored in the user's folder, and cannot be removed by the setup program. If you want to uninstall RailClone 2 to restore RC 1.x, please use the following procedure:
- Close Max.
- Uninstall RailClone 2 from the Windows Control Panel > Add or Remove Programs.
- Remove the registry key HKEY_CURRENT_USER\Software\Itoo Software\RailClone Pro\LibraryMacros, or run uninstall_RC2.reg
- Delete all files .mcr that use prefix RailClone-RC from the folder C:\Users\<user name>\AppData\Local\Autodesk\3dsmax\2013 - 64bit\ENU\usermacros (replace 2013 - 64 with your Max version)
- Install RailClone 1.x
RC2 uses a new object format. Once converted, it is not possible to come back to version 1. Backup your scenes before editing them with v2.