Platform: All Platforms Applies to: COMSOL Multiphysics® Versions: All versions

Problem Description

The error "Internal evaluation error: unexpected NaN encountered" occurs.


This error occurs when Not-a-Number (NaN) values appear unexpectedly. Such values can be the result of floating-point operations such as 0/0, resulting in undefined or unrepresentable values (see A possible cause is improperly defined coupling operators. As a first step, check that the definitions of the source and destination domains of any coupling operator or periodic boundary conditions are correct.