error when viewing PDFs in emacs resp. after deleting associated buffers

• https://www.reddit.com/r/emacs/comments/4029g0/error_when_viewing_pdfs/

the annoying, recurring error message:

Error running timer `doc-view-display’: (error “Selecting deleted buffer”)

what to do:

M-x cancel-timer doc-view-display

Update 2019-11-05 (GNU Emacs 26.3 on Mojave):

M-x cancel-function-timers doc-view-display