A simple Plot doesn't work in Qt5

[8Observer8]

Looks like you are using the release version of the lib in a debug app

In the pro file try

LIBS += -L$${QWT_LOCATION}/lib -lqwtd

note the -lqwtd instead of -lqwt

Yes, It works! Thank you very much

[Uwe]

To avoid issues like this: http://qwt.sourceforge.net/qwtinstal...PILEANDLINKAPP

Uwe