GLASS mod in forge not launching

When I installed forge 1.12.2, (version 14.23.5.2838) I intended to use the mod "GLASS (General Layman's Aesthetic Spying Screen)." And the first time I launched it, everything worked perfectly as intended. Then, 1 day later, I try to launch it, and when I do, I receive the message, "Error! Unable to start game." The mods and their versions are: GLASS 7.0.0, iChunUtil 1.7.1, and Optifine 1.12.2 HD_U_E3.