The real error is here:
Code:
Exception Type: EXC_BAD_ACCESS (SIGKILL (Code Signature Invalid))
Exception Codes: UNKNOWN_0x32 at 0x0000000109ef0000
Exception Codes: 0x0000000000000032, 0x0000000109ef0000
Termination Reason: Namespace CODESIGNING, Code 2 Invalid Page
For some reason, your machine is still testing the code signatures in a BETA build of Sigil that is UNSIGNED.
It should not be doing that.
Which version of macOS are you using?