- 
    
Bug
 - 
    Resolution: Done
 - 
    
P3: Somewhat important
 - 
    None
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    Qt Creator 4.7.0
 - 
    None
 
Self-explanatory I guess.

This happens on windows 10 64 bit when tool-chains are MinGW 32bit for pre-built Qt5.4.2 and Qt5.10.1, but not for self-built Qt5.9.3 with MinGW 64bit.
Vector3D is
typedef Vector3T <double> Vector3D;
which might have an effect on this.