When Loading World, it crashes Minecraft (working world before)

Starts with

java.lang.IllegalStateException: failed to create a child event loop

Minecraft was working just fine for the two days it's been installed on this Lenovo laptop... and it suddenly crapped out when pushing the ESC button to get out of the chest. Trying to reload the World (that worked before), Minecraft craps out to the console and spits out the error report that is attached. None of the worlds we have (a few now) work at all. Same crap out message. Other Lenovo laptop (we have two new ones) works fine with its Minecraft. It's this one Lenovo's laptop's Minecraft that now craps out.