Glitch in the "contract" screen

[L4NDONORRIS]

Every time I clicked on the "contract" section, the window will start twitching, and purple blocks will appear on the editor instead of the content. Some drivers will not appear, neither does the pop-up window as I clicked on the ones who haven't disappeared yet. On the CMD window it implies that "[ERROR:tile_manager.cc(835)] WARNING: tile memory limits exceeded, some content may not draw"