Derek A

Remember when using coremods to contact their authors before Forge. Additionally, I noticed from your mod list you are using some very unstable mods. For example, you are using Buildcraft 7.99.8.1 which is in alpha, unstable and now unsupported because the mod has moved on to 1.12.2. So I would not recommend trying to use it. You could add each mod individually to find out which ones are the source of your problem.