Did you try reinstalling the program, as the message suggested?
Please follow the solution at the below to install the missing DLL component:
If that doesn't resolve the issue you may also need to reinstall LR as JimHess suggested.
Thank you. Reinstalling the missing .dll solved the problem. Not sure how it got clobbered, but your fix worked.
Thanks for your response. I reinstalled the missing .dll which fixed the problem.