diff --git a/fhem/FHEM/00_MAXLAN.pm b/fhem/FHEM/00_MAXLAN.pm
index 9a6e8de5e..d83a5d058 100755
--- a/fhem/FHEM/00_MAXLAN.pm
+++ b/fhem/FHEM/00_MAXLAN.pm
@@ -463,7 +463,7 @@ MAXLAN_Parse($$)
     #One can write to that memory with the "m:" command
     #The actual configuration comes with the "C:" response and can be set
     #with the "s:" command.
-    return if(@args < 3); #On virgin devices, we get nothing, not even $magic$version$numgroups$numdevices
+    return $name if(@args < 3); #On virgin devices, we get nothing, not even $magic$version$numgroups$numdevices
 
     my $bindata = decode_base64($args[2]);
     #$version is the version the serialized data format I guess
@@ -473,7 +473,7 @@ MAXLAN_Parse($$)
       1;
     } or do {
       Log 1, "MAXLAN_Parse: Metadata response is malformed!";
-      return;
+      return $name;
     };
     
     if($magic != $metadata_magic || $version != $metadata_version) {
@@ -504,12 +504,12 @@ MAXLAN_Parse($$)
     #Log $ll5, "Got Metadata, hash: ".Dumper($hash);
 
   }elsif($cmd eq "C"){#Configuration
-    return if(@args < 2);
+    return $name if(@args < 2);
     my $bindata = decode_base64($args[1]);
 
     if(length($bindata) < 18) {
       Log 1, "Invalid C: response, not enough data";
-      return "MAXLAN_Parse: Invalid C: response, not enough data";
+      return $name;
     }
 
     #Parse the first 18 bytes, those are send for every device
@@ -522,7 +522,7 @@ MAXLAN_Parse($$)
 
     if($len != length($bindata)) {
       Dispatch($hash, "MAX,1,Error,$addr,Parts of configuration are missing", {RAWMSG => $rmsg});
-      return "MAXLAN_Parse: Invalid C: response, len does not match";
+      return $name;
     }
 
     #devicetype: Cube = 0, HeatingThermostat = 1, HeatingThermostatPlus = 2, WallMountedThermostat = 3, ShutterContact = 4, PushButton = 5
@@ -626,7 +626,7 @@ MAXLAN_Parse($$)
     if(@args==0){
       $hash->{STATE} = "initalized"; #pairing ended
       $hash->{pairmode} = 0;
-      return undef;
+      return $name;
     }
     my ($type, $addr, $serial) = unpack("CH6a[10]", decode_base64($args[0]));
     Log 2, "MAXLAN_Parse: Paired new device, type $device_types{$type}, addr $addr, serial $serial";
@@ -645,12 +645,10 @@ MAXLAN_Parse($$)
     Log 3, "MAXLAN_Parse: 1% rule: we sent too much, cmd is now in queue" if($hash->{dutycycle} == 100 && $hash->{freememoryslot} > 0);
     Log 2, "MAXLAN_Parse: 1% rule: we sent too much, queue is full" if($hash->{dutycycle} == 100 && $hash->{freememoryslot} == 0);
     Log 2, "MAXLAN_Parse: Command was discarded" if($discarded);
-    return "Command was discarded" if($discarded);
   } else {
-    Log $ll5, "$name Unknown command $cmd";
-    return "MAXLAN_Parse: Unknown command $cmd";
+    Log 2, "MAXLAN_Parse: Unknown command $cmd";
   }
-  return undef;
+  return $name;
 }
 
 
diff --git a/fhem/FHEM/10_MAX.pm b/fhem/FHEM/10_MAX.pm
index 90fb73565..e64844e89 100755
--- a/fhem/FHEM/10_MAX.pm
+++ b/fhem/FHEM/10_MAX.pm
@@ -427,7 +427,7 @@ MAX_Parse($$)
   my ($MAX,$isToMe,$msgtype,$addr,@args) = split(",",$msg);
   #$isToMe is 1 if the message was direct at the device $hash, and 0
   #if we just snooped a message directed at a different device (by CUL_MAX).
-  return if($MAX ne "MAX");
+  return () if($MAX ne "MAX");
 
   Log 5, "MAX_Parse $msg";
   #Find the device with the given addr
diff --git a/fhem/FHEM/14_CUL_MAX.pm b/fhem/FHEM/14_CUL_MAX.pm
index b885b9901..d9c9ac40b 100644
--- a/fhem/FHEM/14_CUL_MAX.pm
+++ b/fhem/FHEM/14_CUL_MAX.pm
@@ -157,13 +157,13 @@ CUL_MAX_Parse($$)
   }
   my $shash = $modules{CUL_MAX}{defptr};
 
-  $rmsg =~ m/Z(..)(..)(..)(..)(......)(......)(..)(.*)/;
+  return () if($rmsg !~ m/Z(..)(..)(..)(..)(......)(......)(..)(.*)/);
+
   my ($len,$msgcnt,$msgFlag,$msgTypeRaw,$src,$dst,$groupid,$payload) = ($1,$2,$3,$4,$5,$6,$7,$8);
   $len = hex($len);
   if(2*$len+3 != length($rmsg)) { #+3 = +1 for 'Z' and +2 for len field in hex
-    my $msg = "CUL_MAX_Parse: len mismatch";
-    Log 1, $msg;
-    return $msg;
+    Log 1, "CUL_MAX_Parse: len mismatch";
+    return $shash->{NAME};
   }
 
   $groupid = hex($groupid);
@@ -178,10 +178,10 @@ CUL_MAX_Parse($$)
   if(exists($msgId2Cmd{$msgTypeRaw})) {
 
     if($msgType eq "Ack") {
-      return undef if($src eq $shash->{addr}); #Ignore packets generated by culfw's auto-Ack
+      return $shash->{NAME} if($src eq $shash->{addr}); #Ignore packets generated by culfw's auto-Ack
       Dispatch($shash, "MAX,$isToMe,Ack,$src,$payload", {RAWMSG => $rmsg});
 
-      return undef if(!$isToMe);
+      return $shash->{NAME} if(!$isToMe);
 
       my $i = 0;
       while ($i < @waitForAck) {
@@ -189,7 +189,7 @@ CUL_MAX_Parse($$)
         if($packet->{dest} eq $src and $packet->{cnt} == hex($msgcnt)) {
           Log 5, "Got matching ack";
           splice @waitForAck, $i, 1;
-          return undef;
+          return $shash->{NAME};
         } else {
           $i++;
         }
@@ -224,7 +224,7 @@ CUL_MAX_Parse($$)
       #2. It is sent after changing batteries or repressing the pair button (without factory reset) and has a destination address of the last paired device. We can answer it with PairPong and even get an Ack, but it will still not be paired to us. A factory reset (originating from the last paired device) is needed first.
       if(($dst ne "000000") and !$isToMe) {
         Log 2, "Device want's to be re-paired to $dst, not to us";
-        return undef;
+        return $shash->{NAME};
       }
 
       if($shash->{pairmode}) {
@@ -248,7 +248,7 @@ CUL_MAX_Parse($$)
   } else {
     Log 2, "CUL_MAX_Parse: Got unhandled message type $msgTypeRaw";
   }
-  return undef;
+  return $shash->{NAME};
 }
 
 sub