Pradeep,
Sorry that you are seeing this issue. The problem you are reporting is not the normal behavior with Darkest Dark.
Can you please send us the 3-4 thread dumps when the STS freezes to help us investigate further?
Also send us the workspace log located at workspace dir/.metadata/.log.
Here is Eclipse page on how to get thread dump: https://wiki.eclipse.org/How_to_report_a_deadlock . Preferably use jstack [pid] > thread_dump.txt. Please let me know if you have trouble getting the thread dump.
Apologies for inconvenience caused.
–Swapna
MyEclipse Support