The org-encrypt-entry fails to encrypt an entry, with a wrong-type-argument. I am currently using doom-emacs, and created a corresponding issue (https://github.com/hlissner/doom-emacs/issues/3123), where I was told to report the issue upstream. As hlissner mentioned in the above issue, it seems to be that the issue is the org-encrypt-string function expects epa-file-encrypt-to to be a string, but epa-file-encrypt-to's documentation says 'May either be a string or a list of strings.'. Doom-emacs sets it to a list of strings.
Backtrace: Debugger entered--Lisp error: (wrong-type-argument stringp stringp) format-message(stringp) apply(format-message stringp) error(stringp) org-encrypt-entry() funcall-interactively(org-encrypt-entry) call-interactively(org-encrypt-entry record nil) command-execute(org-encrypt-entry record) counsel-M-x-action("org-encrypt-entry") ivy-call() ivy-read("M-x " ("org-encrypt-entry" "doom/toggle-debug-mode" "org-encrypt-entries" "org-decrypt-entry" "cd" "5x5" "amx" "arp" "dbx" "dig" "erc" "ert" "eww" "ftp" "gdb" "irc" "jdb" "man" "mpc" "pdb" "pwd" "rsh" "sdb" "xdb" "calc" "deft" "diff" "dirs" "ffap" "gnus" "grep" "help" "ielm" "info" "life" "lsp!" "mail" "mpuz" "ping" "pong" "talk" "term" "undo" "yank" "zone" "align" "chmod" "debug" "diary" "dired" ...) :predicate #f(compiled-function (x) #<bytecode 0x298e655>) :require-match t :history counsel-M-x-history :action counsel-M-x-action :keymap (keymap (67108908 . counsel--info-lookup-symbol) (67108910 . counsel-find-symbol)) :initial-input nil :caller counsel-M-x) counsel-M-x() funcall-interactively(counsel-M-x) call-interactively(counsel-M-x nil nil) command-execute(counsel-M-x) Emacs : GNU Emacs 26.3 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.10) of 2019-08-30 Package: Org mode version 9.4 (nil @ /home/silipwn/.emacs.d/.local/straight/build/org-mode/)