I have installed Ubuntu 18.04.5 beside Windows10 (after Windows10). The Ubuntu-System runs properly, but I cannot install Software or refresh the System. "Sudo" requests for the administrator password, as all other system- related actions. Means, I have no chance to reach the administrator platform (#). Always the message: Wrong password, but I use the right password. What can I do? Thanks.
Using the recent Ubuntu distributions (up to 18.10.), after installation of Qt software, I could see and start the Qt-Creator in the application window. Now I have installed Ubuntu 19.10. and Qt 5.12.6 and there is no more Qt-Creator Button in the application window. Hence, I have the problem, that I don't know, how to start Qt-Creator. I am asking for a solution. The button should apper within the buttos below.
I had several tutorial videos stored on my computer, I could run them all, while Ubuntu 16.04.was installed.
Since I have installed Ubuntu 18.10, it is not possible to play any video. I always get the message: File cannot be played, H264-Decoder is necessary.
In the Ubuntu Wiki can't find a solution.
Can someone help? Please!
This post has been translated from German. For the original, please see the revision history.
I have written the following program in Qt Creator.
The error message refers to Ubuntu. I'm using Ubuntu 18.04 on a device with Intel i5.
I've been researching for days and have not found a solution yet.
What could be the problem and how can I fix it?
#include <QApplication>
#include <QPushButton>
int main(int argc, char* argv[])
{
QApplication app(argc, argv);
QPushButton button("Hallo Welt und so weiter");
button.move(250,300);
button.show();
return app.exec();
}
:-1: Fehler: collect2: error: ld returned 1 exit status
g++ -Wl,-rpath,/opt/Qt/5.11.1/gcc_64/lib -o HalloWelt main.o -L/opt/Qt/5.11.1/gcc_64/lib -lQt5Widgets -lQt5Gui -lQt5Core -lGL -lpthread
/usr/bin/x86_64-linux-gnu-ld: cannot find -lGL
Makefile:254: recipe for target 'HalloWelt' failed
collect2: error: ld returned 1 exit status
make: *** [HalloWelt] Error 1
16:12:14: Der Prozess "/usr/bin/make" wurde mit dem Rückgabewert 2 beendet.
Fehler beim Erstellen/Deployment des Projekts HalloWelt (Kit: Desktop Qt 5.11.1 GCC 64bit)
Bei der Ausführung von Schritt "Make"
16:12:14: Verstrichene Zeit: 00:00.