Ok, I've found that the results are stored in files Makefile.Release, Makefile.Debug and everything is explained here.

@Ni.Sumi I mean the compiler invocation, not the error (I saw the error in your first post). It should look something like this: g++ -c -pipe -g -std=gnu++0x -Wall -W -D_REENTRANT -fPIC -DQT_QML_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I../../myproject -I. -I../../../qt/qt-5.6/qtbase/include -I../../../qt/qt-5.6/qtbase/include/QtWidgets -I../../../qt/qt-5.6/qtbase/include/QtGui -I../../../qt/qt-5.6/qtbase/include/QtCore -I. -I../../../qt/qt-5.6/qtbase/mkspecs/linux-g++ -o somesource.o ../../myproject/somesource.cpp / I've taken it from g++, but you get the idea - the compile line, the call that compiles the offending source. / Kind regards.

I am not involved in the encoding part. I did not write one single code for encoding. I get 3rd party XML files and i just want to decode them. To be very clear on this: I can't change the encoding, it is not my software, i do not develop it and i never had. I just got the source code for the de and encrypt part, so i may be able to import the XML files. I never wrote a single line VB code in my life. To be honest, i don't believe security is the issue, the developer just don't want anyone to be able to open it. That may not be an excuse for bad code but so far, i can't change it, i'm just happy now to be able to decode.

You cannot compile Qt applications without Qt. How should it work? QtCreator is not needed to build Qt based applications. The other person has to install Qt for VS2013.

<walks away with head down>... @Leonardo Thanks!

OK, I rebuilt Qt 5.5.0 after removing the environment variables, but it unfortunately did not solve the problems I described. I was ultimately able to get the VS addin 1.2.4 working in VS 2013 by specifying the Qt installation as being at C:\Qt\5.5.0\qtbase instead of just C:\Qt\5.5.0. I was able to create a simple Qt GUI program and run both Debug and Release builds. But the remaining problem is that all Qt tools like designer, assistant, and linguist all crash as soon as they are started. In each case the event log holds an entry like this, Faulting application name: designer.exe, version: 1.0.0.0, time stamp: 0x55d4a1df Faulting module name: Qt5Gui.dll, version: 5.5.0.0, time stamp: 0x55d48d34 Exception code: 0xc0000005 Fault offset: 0x00000000006850f5 Faulting process id: 0x5b8 Faulting application start time: 0x01d0daadb7408ac1 Faulting application path: C:\Qt\5.5.0\qtbase\bin\designer.exe Faulting module path: C:\Qt\5.5.0\qtbase\bin\Qt5Gui.dll Report Id: f504ee37-46a0-11e5-8267-8cdcd42c37a6 Faulting package full name: Faulting package-relative application ID: So there is still some kind of issue with my build, though my simple Qt GUI project was evidently able to use Qt5Gui.dll without a problem. Any idea what could be causing this? Is there a problem with the configure options I chose? Or with the modifications I had to make to qcompilerdetection.h to get the build to work? Thanks, Paul

Well, if you've been using it already for so long and you didn't find it frustrating then it's okay, my comment was only for newbies (and you're no longer in that category after months of using it)