diff --git a/package.json b/package.json
index 7475ef1e..3921cc4e 100644
--- a/package.json
+++ b/package.json
@@ -18,8 +18,8 @@
     "@abaplint/cli": "^2.113.108",
     "@abaplint/database-pg": "^2.10.24",
     "@abaplint/database-sqlite": "^2.10.24",
-    "@abaplint/runtime": "^2.10.34",
-    "@abaplint/transpiler-cli": "^2.10.34",
+    "@abaplint/runtime": "^2.10.37",
+    "@abaplint/transpiler-cli": "^2.10.37",
     "0x": "^5.8.0"
   }
 }
diff --git a/src/kernel/kernel_create_data_handle.clas.abap b/src/kernel/kernel_create_data_handle.clas.abap
index 7b7478cf..597babf1 100644
--- a/src/kernel/kernel_create_data_handle.clas.abap
+++ b/src/kernel/kernel_create_data_handle.clas.abap
@@ -31,7 +31,9 @@ ENDCLASS.
 CLASS kernel_create_data_handle IMPLEMENTATION.
 
   METHOD call.
-    ASSERT handle IS BOUND.
+    IF handle IS NOT BOUND.
+      RAISE EXCEPTION TYPE cx_sy_ref_is_initial.
+    ENDIF.
 
     WRITE '@KERNEL if (dref.constructor.name === "FieldSymbol") {'.
     WRITE '@KERNEL   dref = dref.getPointer();'.
diff --git a/src/tcp/cl_apc_tcp_client_manager.clas.locals_imp.abap b/src/tcp/cl_apc_tcp_client_manager.clas.locals_imp.abap
index fb5a6bdf..049e4856 100644
--- a/src/tcp/cl_apc_tcp_client_manager.clas.locals_imp.abap
+++ b/src/tcp/cl_apc_tcp_client_manager.clas.locals_imp.abap
@@ -63,8 +63,8 @@ CLASS lcl_client IMPLEMENTATION.
 *    WRITE '@KERNEL   console.dir(data);'.
     WRITE '@KERNEL   await this.mo_handler.get().if_apc_wsp_event_handler$on_message({i_message: msg});'.
     WRITE '@KERNEL });'.
-    WRITE '@KERNEL this.client.on("end",   async () => {this.mo_handler.get().if_apc_wsp_event_handler$on_close();});'.
-    WRITE '@KERNEL this.client.on("error", async (e) => {this.mo_handler.get().if_apc_wsp_event_handler$on_error();});'.
+    WRITE '@KERNEL this.client.on("end",   async () => {this.mo_handler.get().if_apc_wsp_event_handler$on_close({"i_reason": "connection closed"});});'.
+    WRITE '@KERNEL this.client.on("error", async (e) => {console.dir("IF_APC_WSP_CLIENT~CONNECT"); console.dir(e); this.mo_handler.get().if_apc_wsp_event_handler$on_error({"i_reason": e.toString()});});'.
     WRITE '@KERNEL await new Promise(resolve => this.client.once("connect", resolve));'.
   ENDMETHOD.
 
diff --git a/src/tcp/if_apc_wsp_event_handler.intf.abap b/src/tcp/if_apc_wsp_event_handler.intf.abap
index 85f0e18f..8d4d5a2b 100644
--- a/src/tcp/if_apc_wsp_event_handler.intf.abap
+++ b/src/tcp/if_apc_wsp_event_handler.intf.abap
@@ -2,9 +2,12 @@ INTERFACE if_apc_wsp_event_handler PUBLIC.
   METHODS on_open.
 
   METHODS on_message
-    IMPORTING i_message TYPE REF TO if_apc_wsp_message.
+    IMPORTING
+      i_message TYPE REF TO if_apc_wsp_message.
 
-  METHODS on_close.
+  METHODS on_close
+    IMPORTING
+      i_reason TYPE string.
 
   METHODS on_error
     IMPORTING
diff --git a/test/cl_apc_tcp_client_manager.clas.testclasses.abap b/test/cl_apc_tcp_client_manager.clas.testclasses.abap
index 2b719b5f..eac6e55f 100644
--- a/test/cl_apc_tcp_client_manager.clas.testclasses.abap
+++ b/test/cl_apc_tcp_client_manager.clas.testclasses.abap
@@ -2,6 +2,7 @@ CLASS lcl_handler DEFINITION FINAL.
   PUBLIC SECTION.
     INTERFACES if_apc_wsp_event_handler.
     DATA message TYPE xstring.
+    DATA error_reason TYPE string.
 ENDCLASS.
 
 CLASS lcl_handler IMPLEMENTATION.
@@ -19,7 +20,7 @@ CLASS lcl_handler IMPLEMENTATION.
   ENDMETHOD.
 
   METHOD if_apc_wsp_event_handler~on_error.
-    WRITE / 'on_error'.
+    error_reason = i_reason.
   ENDMETHOD.
 ENDCLASS.
 
@@ -30,6 +31,7 @@ CLASS ltcl_tcp DEFINITION FOR TESTING RISK LEVEL HARMLESS DURATION MEDIUM FINAL.
 
     METHODS port_80 FOR TESTING RAISING cx_static_check.
     METHODS port_443 FOR TESTING RAISING cx_static_check.
+    METHODS on_error FOR TESTING RAISING cx_static_check.
 
 ENDCLASS.
 
@@ -79,4 +81,31 @@ CLASS ltcl_tcp IMPLEMENTATION.
     test_port( '443' ).
   ENDMETHOD.
 
+  METHOD on_error.
+
+    DATA lo_handler         TYPE REF TO lcl_handler.
+    DATA li_client          TYPE REF TO if_apc_wsp_client.
+    DATA ls_frame           TYPE if_abap_channel_types=>ty_apc_tcp_frame.
+    DATA li_message_manager TYPE REF TO if_apc_wsp_message_manager.
+    DATA li_message         TYPE REF TO if_apc_wsp_message.
+
+    CREATE OBJECT lo_handler.
+
+    ls_frame-frame_type   = if_apc_tcp_frame_types=>co_frame_type_fixed_length.
+    ls_frame-fixed_length = 10.
+
+    li_client = cl_apc_tcp_client_manager=>create(
+      i_host          = 'somethingerror.org'
+      i_port          = '12345'
+      i_frame         = ls_frame
+      i_event_handler = lo_handler ).
+
+    " li_client->connect( ).
+
+    " cl_abap_unit_assert=>assert_equals(
+    "   act = lo_handler->error_reason
+    "   exp = 'todo' ).
+
+  ENDMETHOD.
+
 ENDCLASS.
\ No newline at end of file