MPS-19849 [build:MPS-135.938] Listener was not added to a containing model of current node. Editor: jetbrains.mps.nodeEditor.NodeEditorComponent[,0,0,0x0,invalid,layout=jetbrains.mps.nodeEditor.EditorComponentLayoutManager,alignmentX=0.0,alignmentY=0.0,border=,flags=321,maximumSize=,minimumSize=,preferredSize=] modelId: f:project#3f233e7f-b8a6-46d2-a57f-795d56775243 models with listeners: r:aa31e43e-9240-4f4d-b6db-5c1c9a86c59e: Listener was not added to a containing model of current node. Editor: jetbrains.mps.nodeEditor.NodeEditorComponent[,0,0,0x0,invalid,layout=jetbrains.mps.nodeEditor.EditorComponentLayoutManager,alignmentX=0.0,alignmentY=0.0,border=,flags=321,maximumSize=,minimumSize=,preferredSize=] modelId: f:project#3f233e7f-b8a6-46d2-a57f-795d56775243 models with listeners: r:aa31e43e-9240-4f4d-b6db-5c1c9a86c59e

- checking SModel.canFireReadEvent() within assertion.
Merge remote-tracking branch 'origin/MPS3.1' into 3.1/editorUsability
MPS-18228 [build:MPS-129.189] <null> : Position -1 is not allowed for EditorCell_Label: ""
fix MPS-19839
updating update.xml because of MPS 3.1 release
fix MPS-19839
Merge remote-tracking branch 'origin/3.1/simon' into 3.1/editorUsability
regenerating after merge