About wireframe:
In the Layer Settings Dialog there is a toggle for each layer to be shaded or wireframe. The state of this toggle is saved for each layer for each individual Layer Combination so switching from one Layer Combination to another when activating a saved View can change the state of this toggle. This could be a reason.
About memory: maybe you have a setting that would require a lot of memory. The first thing that comes to mind is the Grass shader, which can cause this if its settings are set to large values.
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