I receive income from a LIF and T4RIF was issued. I also received T5008 re a portion - doesn't make sense. I assume this t5008 was issued in error. Thoughts?

I would contact your financial advisor or institution. You should not be receiving any T5008s if your investments are held in "registered accounts" such as your LIF. It is possible that a transfer took place, but even then if it was all within your registered account, no T5008 should be issued.