diff --git a/lib/channel/GwChannel.cpp b/lib/channel/GwChannel.cpp
index ef9d64e0..1b098598 100644
--- a/lib/channel/GwChannel.cpp
+++ b/lib/channel/GwChannel.cpp
@@ -106,20 +106,34 @@ void GwChannel::setImpl(GwChannelInterface *impl){
 }
 void GwChannel::updateCounter(const char *msg, bool out)
 {
-    char key[6];
+    char key[7];
+    key[0]=0;
     if (msg[0] == '$')
     {
-        strncpy(key, &msg[3], 3);
+        for (int i=0;i<6 && msg[i] != 0;i++){
+            if (i>=3) {
+                if (isalnum(msg[i]))key[i-3]=msg[i];
+                else key[i-3]='_';
+            }
+            key[i-2]=0;
+        }
         key[3] = 0;
     }
     else if (msg[0] == '!')
     {
-        strncpy(key, &msg[1], 5);
+        for (int i=0;i<6 && msg[i] != 0;i++){
+            if (i>=1) {
+                if (isalnum(msg[i]))key[i-1]=msg[i];
+                else key[i-1]='_';
+            }
+            key[i]=0;
+        }
         key[5] = 0;
     }
     else{
         return;
     }
+    if (key[0] == 0) return;
     if (out){
         countOut->add(key);
     }
diff --git a/lib/serial/GwSerial.cpp b/lib/serial/GwSerial.cpp
index 93278812..640d3403 100644
--- a/lib/serial/GwSerial.cpp
+++ b/lib/serial/GwSerial.cpp
@@ -40,7 +40,7 @@ class GwSerialStream: public Stream{
 
 
 
-GwSerial::GwSerial(GwLog *logger, Stream *s, int id,bool allowRead):serial(s)
+GwSerial::GwSerial(GwLog *logger, HardwareSerial *s, int id,bool allowRead):serial(s)
 {
     LOG_DEBUG(GwLog::DEBUG,"creating GwSerial %p id %d",this,id);
     this->id=id;
@@ -54,6 +54,10 @@ GwSerial::GwSerial(GwLog *logger, Stream *s, int id,bool allowRead):serial(s)
         this->readBuffer=new GwBuffer(logger, GwBuffer::RX_BUFFER_SIZE,bufName+"rd");
     }
     buffer->reset("init");
+    serial->onReceiveError([this](hardwareSerial_error_t err){
+        GwLog *logger=this->logger;
+        LOG_DEBUG(GwLog::ERROR,"serial error on id %d: %d",this->id,(int)err);
+    });
     initialized=true;
 }
 GwSerial::~GwSerial()
diff --git a/lib/serial/GwSerial.h b/lib/serial/GwSerial.h
index d7b01ed5..1cf1920c 100644
--- a/lib/serial/GwSerial.h
+++ b/lib/serial/GwSerial.h
@@ -16,10 +16,10 @@ class GwSerial : public GwChannelInterface{
         int id=-1;
         int overflows=0;
         size_t enqueue(const uint8_t *data, size_t len,bool partial=false);
-        Stream *serial;
+        HardwareSerial *serial;
     public:
         static const int bufferSize=200;
-        GwSerial(GwLog *logger,Stream *stream,int id,bool allowRead=true);
+        GwSerial(GwLog *logger,HardwareSerial *stream,int id,bool allowRead=true);
         ~GwSerial();
         bool isInitialized();
         virtual size_t sendToClients(const char *buf,int sourceId,bool partial=false);
diff --git a/web/index.js b/web/index.js
index 4c90e44f..032b0873 100644
--- a/web/index.js
+++ b/web/index.js
@@ -346,11 +346,15 @@ function createCounterDisplay(parent,label,key,isEven){
         }
     });
 }
-
+function validKey(key){
+    if (! key) return;
+    return key.replace(/[^a-z_:A-Z0-9-]/g,'');
+}
 function updateMsgDetails(key, details) {
     forEl('.msgDetails', function (frame) {
         if (frame.getAttribute('id') !== key) return;
         for (let k in details) {
+            k=validKey(k);
             let el = frame.querySelector("[data-id=\"" + k + "\"] ");
             if (!el) {
                 el = addEl('div', 'row', frame);