.dll file is missing from your computer

[Konstantinos]

I cannot run the .exe file, even I can run the program from the qt creator. The reason is that some .dll files are missing from my computer. So, I am wondering, is there a smart way to find out exactly which .dll files are needed? For example if Qt5core.dll is missing, and I have 20 QT creators (ten 4.x and ten 5.x) in my computer, 20 QT Versions (ten 4.x and ten 5.x), 20 compilers and 20 debuggers (about 160.000 possible combinations of kit), which one of them I have to use? Is there a smart way to find it out?

[Joel Bodenmann]

There's a whole guide on that: Deploying on Windows.

Summary: There is a tool called windeployqt that copies all DLLs that your program requires to run on a Windows computer that doesn't have any Qt stuff installed.

[VRonin]

Dependency walker is invaluable at determining what libraries a binary needs: http://www.dependencywalker.com/

[Konstantinos]

Hi Joel, thanks for your help. After updating and patching all the .dll files (with the command "windeployqt --quick ."), the problem remains, it says that Entry Point Not Found , the procedure entry point __cxa_throw_bad_array_new_length could not be located in the dynamic link library path/Qt5Core.dll.

Let's suppose that I have 20.000 Qt5Core.dll files on my computer and all the Earth has 10^20 Qt5Core.dll files.

Is there a smart way, to understand in my case, which one of those I have to use, and where to find it?

Sorry if my question is stupid.

@VRonin, I know the Dependency Walker, but it just gives you the names of the libraries that a binary needs, not where exactly to find one of them. There are many choices, but most of them create other kinds of problems.

[mrjj]

@Konstantinos said:
The only dlls you should use for a deployment folder is those from your
compiler folder under the Qt folder. like
clang_64, gcc_64, mingw492_32, msvc2013

And it shall match release or debug build.
Debug dlls have d in name.

I like this site for details
http://www.tripleboot.org/?p=138

[crisosphinx]

@Konstantinos It appears you're having the same issue I'm having. QT Creator/ Designer and the .dll files aren't working, even if they exist in their proper locations.

See my thread: https://forum.qt.io/topic/70248/problem-with-launching-exe-or-compiling-and-running-app

Quick question @Konstantinos, do you have Windows 10, and if so, did you get the Anniversary Update?

[Konstantinos]

@mrjj, thanks for the site, I am reading it now.

@crisosphinx yes, the latest version of windows 10. Is it bad? Maybe this creates all the problems?

[crisosphinx]

@Konstantinos Does your program compile and run in creator? Or does it not? If it doesn't, we have the exact same issue, I think.

Yeah, the update has caused issues for a lot of people, but I think QT users are just starting to get effected. Keep me updated on any information, please.

[Konstantinos]

@crisosphinx you are right. After many experiments in other computers, and other virtual machines, and after strong study, I concluded that the problem derives from Windows 10. In Windows 7 everything is under control but in Windows 10 there is a chaotic situation. Especially with QT 5. Also QT creator has many other issues in windows 10.

[crisosphinx]

@Konstantinos Whew, glad to know I'm not the only one. It helps me confirm that I'm not crazy. ;)

[crisosphinx]

@Konstantinos UPDATE:

I seem to have fixed my issue by enabling Developer Mode in Windows 10... Perhaps this solution may fix your issues, too?

https://forum.qt.io/topic/70224/qt-creator-open-source-qt-app-installer-uninstaller-hangs/2