diff --git a/site_ansto/instrument/config/anticollider/anticollider_common.tcl b/site_ansto/instrument/config/anticollider/anticollider_common.tcl
index c9b0ec8a..209a3522 100644
--- a/site_ansto/instrument/config/anticollider/anticollider_common.tcl
+++ b/site_ansto/instrument/config/anticollider/anticollider_common.tcl
@@ -45,13 +45,18 @@ proc handle_acscript_exception {status message args} {
 proc ::anticollider::loadscript {args} {
   variable veto_rules
 
-  set fh [open $::cfPath(anticollider)/[lindex $args 0] RDONLY ]
-  while {[gets $fh line] >= 0} {
-    # Skip empty lines and comments
-    if [regexp {^\s*$|^ *#} $line] {
-      continue
+  catch {
+    set fh [open $::cfPath(anticollider)/[lindex $args 0] RDONLY ]
+    while {[gets $fh line] >= 0} {
+      # Skip empty lines and comments
+      if [regexp {^\s*$|^ *#} $line] {
+        continue
+      }
+      lappend veto_rules $line
     }
-    lappend veto_rules $line
+  }
+  catch {
+    close $fh
   }
 }