Please, show the files of materials state. I didnít see any problems, there is a plastic hinge within the cross section of the bar and also within the cross section of the plates. So everything looks right. The numbers are not completely identical, but, conceptually, the same thing. The analysis stops because of appearance of the unstable structure, and what is the idea of doing like this? By the way, the approximation is not quite successful (1m width with a thickness of 20cm, it shoudnít be neglected for plates), itís also better to set your own deformation law (piecewise linear function), to continue to look for the difference between the results.
By the way (about the approximation), I made the plate slabs to work in accordance with the flat cross-section hypothesis - set perfectly rigid body in every section after what the analysis was end without problems. The plastic hinge formed in two rows of elements from the bearing section, it shows the redistribution, doesnít it? There is only one plastic hinge within the bars. And why the analysis stops I I