Bootstrap updating issue

[ldestrooper]

Currently i'm on 4.0.0.beta3, yet when updating my gem to 4.3.1 i'm getting the following errors when trying to load my server:

Traceback (most recent call last):
	36: from bin/rails:3:in `<main>'
	35: from bin/rails:3:in `load'
	34: from /Users/Desktop/Startover/KTM/bin/spring:15:in `<top (required)>'
	33: from /Users/Desktop/Startover/KTM/bin/spring:15:in `require'
	32: from /Users/.rvm/gems/ruby-2.5.3/gems/spring-2.0.2/lib/spring/binstub.rb:31:in `<top (required)>'
	31: from /Users/.rvm/gems/ruby-2.5.3/gems/spring-2.0.2/lib/spring/binstub.rb:31:in `load'
	30: from /Users/.rvm/gems/ruby-2.5.3/gems/spring-2.0.2/bin/spring:49:in `<top (required)>'
	29: from /Users/.rvm/gems/ruby-2.5.3/gems/spring-2.0.2/lib/spring/client.rb:30:in `run'
	28: from /Users/.rvm/gems/ruby-2.5.3/gems/spring-2.0.2/lib/spring/client/command.rb:7:in `call'
	27: from /Users/.rvm/gems/ruby-2.5.3/gems/spring-2.0.2/lib/spring/client/rails.rb:28:in `call'
	26: from /Users/.rvm/gems/ruby-2.5.3/gems/spring-2.0.2/lib/spring/client/rails.rb:28:in `load'
	25: from /Users/Desktop/Startover/KTM/bin/rails:9:in `<top (required)>'
	24: from /Users/Desktop/Startover/KTM/bin/rails:9:in `require'
	23: from /Users/.rvm/gems/ruby-2.5.3/gems/railties-5.0.7/lib/rails/commands.rb:18:in `<top (required)>'
	22: from /Users/.rvm/gems/ruby-2.5.3/gems/railties-5.0.7/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
	21: from /Users/.rvm/gems/ruby-2.5.3/gems/railties-5.0.7/lib/rails/commands/commands_tasks.rb:85:in `server'
	20: from /Users/.rvm/gems/ruby-2.5.3/gems/railties-5.0.7/lib/rails/commands/commands_tasks.rb:85:in `tap'
	19: from /Users/.rvm/gems/ruby-2.5.3/gems/railties-5.0.7/lib/rails/commands/commands_tasks.rb:88:in `block in server'
	18: from /Users/.rvm/gems/ruby-2.5.3/gems/railties-5.0.7/lib/rails/commands/commands_tasks.rb:88:in `require'
	17: from /Users/Desktop/Startover/KTM/config/application.rb:17:in `<top (required)>'
	16: from /Users/.rvm/rubies/ruby-2.5.3/lib/ruby/site_ruby/2.5.0/bundler.rb:114:in `require'
	15: from /Users/.rvm/rubies/ruby-2.5.3/lib/ruby/site_ruby/2.5.0/bundler/runtime.rb:65:in `require'
	14: from /Users/.rvm/rubies/ruby-2.5.3/lib/ruby/site_ruby/2.5.0/bundler/runtime.rb:65:in `each'
	13: from /Users/.rvm/rubies/ruby-2.5.3/lib/ruby/site_ruby/2.5.0/bundler/runtime.rb:76:in `block in require'
	12: from /Users/.rvm/rubies/ruby-2.5.3/lib/ruby/site_ruby/2.5.0/bundler/runtime.rb:76:in `each'
	11: from /Users/.rvm/rubies/ruby-2.5.3/lib/ruby/site_ruby/2.5.0/bundler/runtime.rb:81:in `block (2 levels) in require'
	10: from /Users/.rvm/rubies/ruby-2.5.3/lib/ruby/site_ruby/2.5.0/bundler/runtime.rb:81:in `require'
	 9: from /Users/.rvm/gems/ruby-2.5.3/gems/bootstrap-4.3.1/lib/bootstrap.rb:75:in `<top (required)>'
	 8: from /Users/.rvm/gems/ruby-2.5.3/gems/bootstrap-4.3.1/lib/bootstrap.rb:11:in `load!'
	 7: from /Users/.rvm/gems/ruby-2.5.3/gems/bootstrap-4.3.1/lib/bootstrap.rb:61:in `register_rails_engine'
	 6: from /Users/.rvm/gems/ruby-2.5.3/gems/bootstrap-4.3.1/lib/bootstrap.rb:61:in `require'
	 5: from /Users/.rvm/gems/ruby-2.5.3/gems/bootstrap-4.3.1/lib/bootstrap/engine.rb:4:in `<top (required)>'
	 4: from /Users/.rvm/gems/ruby-2.5.3/gems/bootstrap-4.3.1/lib/bootstrap/engine.rb:4:in `require'
	 3: from /Users/.rvm/gems/ruby-2.5.3/gems/sassc-rails-2.1.2/lib/sassc-rails.rb:3:in `<top (required)>'
	 2: from /Users/.rvm/gems/ruby-2.5.3/gems/sassc-rails-2.1.2/lib/sassc-rails.rb:3:in `require_relative'
	 1: from /Users/.rvm/gems/ruby-2.5.3/gems/sassc-rails-2.1.2/lib/sassc/rails.rb:5:in `<top (required)>'
/Users/.rvm/gems/ruby-2.5.3/gems/sassc-rails-2.1.2/lib/sassc/rails.rb:5:in `require': cannot load such file -- sassc (LoadError)

Anyone has an idea what the issue is or how to debug the exact issue when my server won't load and won't give more detail?