Steps to reproduce:

1) Download attached project 'MeshRendererError.zip' and open in Unity
2) Open scene 'ReproScene' and press Play
3) Click on IndividualSoldier gameObject in Hierarchy tab
4) Click on Scene view and press F to focus on that gameObject
5) Check the Console tab and you will see that each frame error will be thrown :
Enabling or adding a Renderer during rendering; this is not allowed. Renderer '2WK_heavy_infantry_06_combat_walk_StaticFromSkinned' will not be added.
UnityEditor.DockArea:OnGUI()

Expected result: No errors in Console tab
Actual result: Error 'Enabling or adding a Renderer during rendering; this is not allowed. Renderer '2WK_heavy_infantry_06_combat_walk_StaticFromSkinned' will not be added.
UnityEditor.DockArea:OnGUI()' when object is visible on the Scene or Game views

Reproduced with:
5.6.0b8, 5.6.0f3, 2017.1.0b1

Not reproduced with:
5.5.3p1, 5.6.0b7

Regression from:
5.6.0b8

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Fixed in: 5.6.2p1, 2017.1.0f1