# Compile from source - QSocketNotifier errord

**URL:** <https://discourse.slicer.org/t/compile-from-source-qsocketnotifier-errord/28772>\
**Category:** Development\
**Created:** [April 6, 2023, 1:32am UTC](https://discourse.slicer.org/t/compile-from-source-qsocketnotifier-errord/28772 "2023-04-06T01:32:14Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Peng\_Wang](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/peng_wang/32/65535_2.png) [@Peng\_Wang](https://discourse.slicer.org/u/Peng_Wang)\
**Post date:** [April 6, 2023, 1:32am UTC](https://discourse.slicer.org/t/compile-from-source-qsocketnotifier-errord/28772/1 "2023-04-06T01:32:14Z")

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Operating system: Ubuntu 23.04  
Slicer version: 5.3  
I am compiling Slicer from source on Ubuntu. It uses the Qt from system (v5.15.8).  
When I run Slicer from the Slicer-build/ it give the following error and quit after the splash screen,

QSocketNotifier: Can only be used with threads started with QThread

Thanks.

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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:** [April 6, 2023, 1:34am UTC](https://discourse.slicer.org/t/compile-from-source-qsocketnotifier-errord/28772/2 "2023-04-06T01:34:28Z")

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The message may not be related to the crash. Errors are usually due to OpenSSL and Qt, so they are the most likely culprits. Can you get a stack trace?

Does the official Slicer release work well?