I don't use Tank, or Imp Inventory and I never have this issue. While I can
force it to happen by trying to switch characters too quickly, (without Decal running you'd get an error message saying your character is still in the game and to wait a while) I simply count to 5 when changing chars, and never crash. So, if you don't run the plug-ins listed as potential culprits, try waiting for a slow count of 5 between characters, and see if that helps.
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Ling Mei - Veteran Swordswoman

Lingie - Abu's Health-Addicted Support Mage
Directionally Impaired in AC since 1999
The sun itself sees not 'till heaven clears.