FATAL ERROR: net.minecraft.bootstrap.FatalBootstrapError: Unable to download while being forced

FATAL ERROR: net.minecraft.bootstrap.FatalBootstrapError: Unable to download while being forced
at net.minecraft.bootstrap.Bootstrap.execute(Bootstrap.java:95)
at net.minecraft.bootstrap.Bootstrap.main(Bootstrap.java:381)

This comes up on my computer and I cannot play. I searched for answers to no avail. Please tell me what to do....
Thanks!