Hello Dennis,
Don't think this is related to ESXi. Please check the below links -
Windows VM BSOD : "BSOD 0x7E xen.sys" After updating Xentools
https://www.keithit.com/system-thread-exception-not-handled-xensys-bsod_post2018.html
SYSTEM_THREAD_EXCEPTION_NOT_HANDLED (xen.sys)
-Supreet