During the elastic analysis you get the error:
WARNING: Global buckling factor < 1 at «Selfweight»

[NL]: WARNING: Globale knikfactor < 1 bij «Selfweight»
[FR]: WARNING: Coefficient de flambement global < 1 chez «Selfweight»
[ES]: WARNING: Factor de pandeo global < 1 en «Selfweight»
Solution
More information in this article.