--- a/fsl/src/misc_tcl/fsl_exec.tcl	2018-10-23 18:49:44.000000000 +0200
+++ b/fsl/src/misc_tcl/fsl_exec.tcl	2018-11-25 18:52:30.636934316 +0100
@@ -175,6 +175,9 @@
 	set logout ""
     }
 
+    # make sure errorCode is set
+    if { ! [ info exists ::errorCode ] } { set ::errorCode "NONE" }
+
     # run and log the actual command
     if { $do_logout } {
 	fsl:echo $logout "\n$thecommand"