It is important to try and figure out why it is crashing. Callstacks are important for this and there is a persistent log file (In the saved folder) that exists for trying to diagnose crashes that happen really fast.
More often than not when I see crashes when trying to open massive materials it often comes down to ram, so this my be an "Out of memory" crash. Generating shaders for the DDC can be extremely intensive.
Also are these wildcards landscape materials that you are trying to open? Or are they your own old Material instances? if they are your own, It is possible that changes in th