QFormBuilder was unable to create a custom widget of the class 'QwtPlot'

[driven]

When running my apps in debug or release mode, always get this error. The application don't crash but when the app shows the ui page that contains the qwtPlot widget I don't see it and i get the error in the consolle window.

WIN32
QTCreator
QT SDK 2010.02.1 (4.6.2)
mingw32
Qwt-5.2.1

the .pro file has some lines:


...
INCLUDEPATH += . \
src \
C:/qt/Qwt-5.2.1/src
DEFINES += QWT_DLL
LIBS = c:/qt/Qwt-5.2.1/lib/qwt5.dll \
c:/qt/Qwt-5.2.1/lib/qwtd5.dll
...

where I do wrong?

[driven]

Ok, I solved this issue. Simply I forget to execute:

mingw32-make install

from c:\qt\qwt-5.2.1\


shame on me ;)