# Regression associated with Slicer 5.3.0 2023-01-23 has been fixed

**URL:** <https://discourse.slicer.org/t/regression-associated-with-slicer-5-3-0-2023-01-23-has-been-fixed/27424>\
**Category:** Support\
**Created:** [January 23, 2023, 10:36pm UTC](https://discourse.slicer.org/t/regression-associated-with-slicer-5-3-0-2023-01-23-has-been-fixed/27424 "2023-01-23T22:36:14Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![jcfr](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/jcfr/32/17825_2.png) [@jcfr](https://discourse.slicer.org/u/jcfr)\
**Post date:** [January 23, 2023, 10:36pm UTC](https://discourse.slicer.org/t/regression-associated-with-slicer-5-3-0-2023-01-23-has-been-fixed/27424/1 "2023-01-23T22:36:14Z")

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For future reference, the corresponding regression preventing from starting the application has been identified and fixed in [PR-6793](https://github.com/Slicer/Slicer/pull/6793).

🙏@Connor-Bowley, @Sam_Horvath and @lassoan

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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:** [January 24, 2023, 12:06am UTC](https://discourse.slicer.org/t/regression-associated-with-slicer-5-3-0-2023-01-23-has-been-fixed/27424/2 "2023-01-24T00:06:01Z")

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Thanks for the fix. It was my mistake, I touched up a pull request with a seemingly innocent QString formatting change and there was no build error. I didn’t expect that QString::arg could fail completely at runtime like this.

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**Author:** ![jcfr](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/jcfr/32/17825_2.png) [@jcfr](https://discourse.slicer.org/u/jcfr)\
**Post date:** [January 24, 2023, 12:15am UTC](https://discourse.slicer.org/t/regression-associated-with-slicer-5-3-0-2023-01-23-has-been-fixed/27424/3 "2023-01-24T00:15:28Z")

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The root cause of the crash was the missing return statement fixed in [Slicer@cffc0f3e4](https://github.com/Slicer/Slicer/commit/cffc0f3e4757d72e0649f696639059058e77f0e4)

The problematic `.arg()` fixed in [Slicer@08fe34600](https://github.com/Slicer/Slicer/commit/08fe346009554f82e63e7d7aaaaec06c16f0a233) was found out while investigating and would have likely (only) returned an invalid string.