Click , return to the main play screen, select your new profile, and hit Play . Troubleshooting Modern Compatibility Issues
Because 1.8 introduced "Block States" (a massive rewrite of how blocks store data), updating a large mod from 1.7.10 to 1.8 required rewriting thousands of lines of code. Most mod authors simply said, "No thanks." They stayed on 1.7.10. minecraft 1710 java version