There is an issue with the Configuration under Windows 64-bit systems. The Configuration module has been rewritten in C# and is now considered “managed code”. Windows 64 is supposed to emulate 32 bit environments when needed. Unfortunately, in the case of this module, parts of it were running as 64-bit (the C# part) and parts as 32-bit (the C++/Fortran part), hence the problem – this mixed mode isn’t allowed. We had to change the project to force all of the configuration related modules and DLLs to run in 32-bit mode. Unfortunately this wasn't detected until after the release of Version 5.20.

Attached is a ZIP archive that contains the revised files. Extract these to the \program directory and let me know if you have further problems.

Note the date of this post. The associated ZIP archive is valid only until such time as the 1st build for Version 5.20 is released. After that, the "Build" will incorporate this change.