diff --git a/crpptbx/gdat.m b/crpptbx/gdat.m
index db9e37d573bbbc62faf3458e6401a1145476060d..bd2c03f081a466c7ba559d2ec927f0c4a2f5be22 100644
--- a/crpptbx/gdat.m
+++ b/crpptbx/gdat.m
@@ -165,6 +165,9 @@ try
   end
 catch
   warning(['problems calling gdat_' lower(machine_eff)]);
+  if ~exist('gdat_data'); gdat_data.data = []; end
+  if ~exist('gdat_params'); gdat_params.plot = []; end
+  if ~exist('error_status'); error_status = 998; end
   return
 end