diff --git a/FHEM/Blocking.pm b/FHEM/Blocking.pm
index 7ac415ca5..423a1ba63 100644
--- a/FHEM/Blocking.pm
+++ b/FHEM/Blocking.pm
@@ -172,6 +172,8 @@ BlockingStart(;$)
     my $pid = fhemFork;
     if(!defined($pid)) {
       Log 1, "Cannot fork: $!";
+      stacktrace() if(AttrVal("global", "verbose", 1) >= 5);
+      DoTrigger("global", "CANNOT_FORK", 1);
       return $curr;
     }