# There was an issue when running ./Slicer --launch /home/xxx/Qt5.14.2/Tools/QtCreator/bin/qtcreator on Ubuntu 18.04.

**URL:** <https://discourse.slicer.org/t/there-was-an-issue-when-running-slicer-launch-home-xxx-qt5-14-2-tools-qtcreator-bin-qtcreator-on-ubuntu-18-04/40173>\
**Category:** Development\
**Created:** [November 13, 2024, 2:09pm UTC](https://discourse.slicer.org/t/there-was-an-issue-when-running-slicer-launch-home-xxx-qt5-14-2-tools-qtcreator-bin-qtcreator-on-ubuntu-18-04/40173 "2024-11-13T14:09:33Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![tthh7](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/tthh7/32/78516_2.png) [@tthh7](https://discourse.slicer.org/u/tthh7)\
**Post date:** [November 13, 2024, 2:09pm UTC](https://discourse.slicer.org/t/there-was-an-issue-when-running-slicer-launch-home-xxx-qt5-14-2-tools-qtcreator-bin-qtcreator-on-ubuntu-18-04/40173/1 "2024-11-13T14:09:33Z")

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I successfully built Slicer version 5.7.0-2024-11-08 on Ubuntu 18.04 following the instructions in the [Slicer documentation](https://slicer.readthedocs.io/en/latest/developer_guide/build_instructions/linux.html). However, when I try to debug using Qt, I run into an issue. I launched Qt Creator using the command:  
**./Slicer --launch /home/xxx/Qt5.14.2/Tools/QtCreator/bin/qtcreator**

and received this error:  
**Cannot mix incompatible Qt library (version 0x50e02) with this library (version 0x50e01)**  
**error: [/home/xxx/Qt5.14.2/Tools/QtCreator/bin/qtcreator] exit abnormally - Report the problem.**

When building, I used the following cmake command:  
**cmake -DCMAKE\_BUILD\_TYPE:STRING=Debug -DQt5\_DIR=/home/xxx/Qt5.14.2/5.14.2/gcc\_64/lib/cmake/Qt5 …/Slicer**

Could you advise on how to resolve this issue?

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**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [November 13, 2024, 2:13pm UTC](https://discourse.slicer.org/t/there-was-an-issue-when-running-slicer-launch-home-xxx-qt5-14-2-tools-qtcreator-bin-qtcreator-on-ubuntu-18-04/40173/2 "2024-11-13T14:13:56Z")

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I don’t think this would be something specific to Slicer, but it seems to be a quite widely reported problem on Linux with Qt. Please try some of the suggestions that fixed it for others, for example:

> <https://stackoverflow.com/questions/40372537/cannot-mix-incompatible-qt-library-version-0x50501-with-this-library-version>

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**Author:** ![tthh7](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/tthh7/32/78516_2.png) [@tthh7](https://discourse.slicer.org/u/tthh7)\
**Post date:** [November 14, 2024, 1:17am UTC](https://discourse.slicer.org/t/there-was-an-issue-when-running-slicer-launch-home-xxx-qt5-14-2-tools-qtcreator-bin-qtcreator-on-ubuntu-18-04/40173/4 "2024-11-14T01:17:39Z")

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I think I may have identified the problem: on Ubuntu 18.04, I installed Qt 5.14.2 and ran the cmake command `-DQt5_DIR=/home/xxx/Qt5.14.2/5.14.2/gcc_64/lib/cmake/Qt5`. This makes Slicer pull the required libraries from this path, where all the libraries are version 5.14.2. However, when launching Qt Creator using `./Slicer --launch /home/xxx/Qt5.14.2/Tools/QtCreator/bin/qtcreator`, the libraries used by Qt Creator are not from `/home/xxx/Qt5.14.2/5.14.2/gcc_64/lib` but instead from `/home/xxx/Qt5.14.2/Tools/QtCreator/lib/Qt/lib`. The libraries in this path are linked to version 5.14.1