Asterisk 18.1.0 crashes

Asterisk crashes when calling a realtime extension.
Calling the same extension from within the dialplan works fine.

You’d need to provide a backtrace[1]. That being said there is an open issue[2] involving a crash and realtime dialplan.

[1] https://wiki.asterisk.org/wiki/display/AST/Getting+a+Backtrace
[2] https://issues.asterisk.org/jira/browse/ASTERISK-29019