i also had CTD without /3gb switch (XP) but "mem patched" sh3.exe, it was running fine in MP only together with empty campaign mod. (much lower mem needs)
I had a low mem issue (XP and sh3.exe) here what caused the CTD by trying it in campaign mode, because i disabled the /3gb switch, which is causing problems when running SH5, but this is easy selectable using boot menue.
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Stormy......
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