[Baertram]

I'm not sure the crash happens because of these messages though, they are only "hints" to the devs/ZOs.
I'm pretty sure the crash happens because of an addon itsself then.

I'd check which of the addons names is generating the most errors and disable that at least. Maybe it will fix the crash then at least.
If not, disable the 2nd most named addon, and so on.

And those addons, with the most named entries in the log file, should get a comment from you describing how to rebuild these log entries, and copy them there for the dev so she/he can see what to change at which control.

Explanation:
>has a set height but has resizeToFitDescendents enabled. If this is intended, use resizeToFitConstrains="X"
Means that the dev has used a fixed <dimensions width="number" height="number"> in the XML definition of his control,
or he used the lua code to set <control>:SetDimensions(numberWidth, numberHeight).
But he also enabled the resizeToFitDescendents ="true" or <control>:SetResizeToFitDescendents(true)
which should resize the control if the parent control resizes.

That won't happen though as the dimensions were set as fixed width and height.
So the dev needs to either disable resizeToFitDescendents on these controls or disable the fixed dimensions and use dimension constrainst (maximum width and height but no minimum), or in addition to the resizeToFitDescendents="true" also specify resizeToFitConstrains="x" or "y" to tell the code that the control can resize on the x (width) or y (height) axis up to the constraints that were set.