Fixed Grid GUI crash, fixes #1469

CHANGELOG.md

@@ -3,6 +3,7 @@
 ### 1.5.19
 - Updated Forge to 2493 (MC 1.12.2) (raoulvdberge)
 - Fixed RS blocks requiring a pickaxe to be broken (raoulvdberge)
+- Fixed Grid GUI crash (raoulvdberge)
 
 ### 1.5.18
 - Added Project E integration for the External Storage on the Transmutation Table (raoulvdberge)

src/main/java/com/raoulvdberge/refinedstorage/gui/grid/GuiGrid.java

@@ -230,9 +230,14 @@ public class GuiGrid extends GuiBase implements IGridDisplay {
             scrollbar.setMaxOffset(getRows() - getVisibleRows());
         }
 
+        if (tabPageLeft != null) {
             tabPageLeft.visible = grid.getTotalTabPages() > 0;
+        }
+
+        if (tabPageRight != null) {
             tabPageRight.visible = grid.getTotalTabPages() > 0;
         }
+    }
 
     @Override
     public void update(int x, int y) {