Error: BufReadPost - Unknown function and Invalid expression

[TamaMcGlinn]

When I try to open a new buffer, even vim helpfiles, or the quickfix window, I sometimes get the following error:

Error detected while processing BufReadPost Autocommands for "*":
E117: Unknown function: conflict_marker#detect#markers
E15: Invalid expression: conflict_marker#detect#markers() | call s:on_detected() | endif

The plugin used to work fine. I'm still in the process of narrowing down what in my vimrc is conflicting with conflict-marker. With a vimrc that does nothing but load this plugin using dein, I still get 'Unknown function' when I try to :call conflict_marker#detect#markers(). Is that normal?