diff --git a/@CVC_checker/generate_file.m b/@CVC_checker/generate_file.m
index 953a5817779a18fc97e18768bf4718412493f942..68990c4b159af510dc82090e1aad800342f264a2 100644
--- a/@CVC_checker/generate_file.m
+++ b/@CVC_checker/generate_file.m
@@ -39,7 +39,7 @@ if size(object.data.Grid2.cells,2) > 1
 end
 code = [code new_code];
 
-if size(object.data.Grid1.cells,2) > 1
+if object.data.multi_mode == 0 && size(object.data.Grid1.cells,2) > 1
     [new_code,new_queries] = CVC_checker.generate_cvc_grid(object.data.Grid1,size(queries,2));
     queries = [queries new_queries];
     code = [code new_code];
diff --git a/@GUI/check_grid_condition.m b/@GUI/check_grid_condition.m
index 8b0fb7ca1f316b122bcc6e4ffe5585069aa91c4a..e21eec69b988cc796d05ed6be95ae251faf5a705 100644
--- a/@GUI/check_grid_condition.m
+++ b/@GUI/check_grid_condition.m
@@ -17,11 +17,13 @@ for i = 1:size(grid.cells,2)
     error = '';
     string = get(grid.cells(i).cond,'String');
 
-    s = [string(1,:)];
-    for j = 2:size(string,1)
-       s = [s ' ' string(j,:)];
+    if size(string) > 0
+        s = [string(1,:)];
+        for j = 2:size(string,1)
+           s = [s ' ' string(j,:)];
+        end
+        string = s;
     end
-    string = s;
     
     if ( strcmp(string,'') || isempty(string)) && i == 1 && isempty(grid.parent_grid) && size(grid.cells,2) == 1
         break;
diff --git a/@PVS_checker/pvs_check_for_imports_g.m b/@PVS_checker/pvs_check_for_imports_g.m
index 59704315f0e060d0cf0fb27050889a315506f7cd..f49e9d6493ff86ea9d981070be2f14ec186c4b4d 100644
--- a/@PVS_checker/pvs_check_for_imports_g.m
+++ b/@PVS_checker/pvs_check_for_imports_g.m
@@ -24,11 +24,13 @@ for i=1:size(grid.cells,2)
     end
     text = char(grid.cells(i).cond_text);
 
-    s = [text(1,:)];
-    for j = 2:size(text,1)
-       s = [s ' ' text(j,:)];
+    if size(text) > 0
+        s = [text(1,:)];
+        for j = 2:size(text,1)
+           s = [s ' ' text(j,:)];
+        end
+        text = s;
     end
-    text = s;
     
     vars = regexp(text,'([a-zA-Z][a-zA-Z0-9_]*)','match');