Hello, To start off, this issue is not specific to emacs 27. I have been noticing this issue for maybe one or two weeks and just to formally reporting it. Issue: When doing desktop-read, only files from a certain project root cause these errors: File mode specification error: (wrong-type-argument stringp nil) [2 times] Digging deeper, it looks like the set-auto-mode call in normal-mode is returning nil. But it is surprising because the files for which this error shows up does actually have an associated major mode (verilog-mode). After the desktop loads, I am able to see the files that flagged that error properly in the correct major mode though. Here is the error backtrace: (*I have replaced the actual path with /my/prj/root/some.file for the purpose of corporate privacy. The some.file is has verilog-mode as its major mode.) Debugger entered--Lisp error: "File mode specification error: (wrong-type-argument stringp nil)" #("File mode specification error: %s" (wrong-type-argument stringp nil)) apply(# ("File mode specification error: %s" (wrong-type-argument stringp nil))) message("File mode specification error: %s" (wrong-type-argument stringp nil)) normal-mode(t) after-find-file(nil nil) find-file-noselect-1(# "/my/prj/root/some.file" :nowarn nil "/my/prj/root/some.file" (96434279 175)) find-file-noselect("/my/prj/root/some.file" :nowarn) desktop-restore-file-buffer("/my/prj/root/some.file" "some.file" nil) desktop-create-buffer(208 "/my/prj/root/some.file" "some.file" verilog-mode (abbrev-mode override-global-mode modi-mode beacon-mode hi-lock-mode volatile-highlights-mode hungry-delete-mode rainbow-delimiters-mode undo-tree-mode projectile-mode hardcore-mode ivy-mode which-key-mode flyspell-mode yas-minor-mode auto-complete-mode mode-line-space-mode) 6362 (19911 nil) t nil ((buffer-display-time 22952 2660 236587 832000) (buffer-file-coding-system . undecided-unix)) ((mark-ring (19911)))) eval-buffer(# nil "/home/kmodi/.emacs.d/emacs_27_0.desktop" nil t) ; Reading at buffer position 67828 In GNU Emacs 27.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 2.24.23) of 2017-09-16 Repository revision: 977cd6cb28a37744966ec62f70cf62659f6f302a Windowing system distributor 'The X.Org Foundation', version 11.0.60900000 System Description: Red Hat Enterprise Linux Workstation release 6.6 (Santiago) Recent messages: For information about GNU Emacs and the GNU system, type C-h C-a. Configured using: 'configure --with-modules --prefix=/home/kmodi/usr_local/apps/6/emacs/master '--program-transform-name=s/^ctags$/ctags_emacs/' 'CPPFLAGS=-I/home/kmodi/usr_local/6/include -I/usr/include/freetype2 -I/usr/include' 'CFLAGS=-ggdb3 -O0' 'CXXFLAGS=-ggdb3 -O0' 'LDFLAGS=-L/home/kmodi/usr_local/6/lib -L/home/kmodi/usr_local/6/lib64 -ggdb3' PKG_CONFIG_PATH=/home/kmodi/usr_local/6/lib/pkgconfig:/home/kmodi/usr_local/6/lib64/pkgconfig:/cad/adi/apps/gnu/linux/x86_64/6/lib/pkgconfig:/cad/adi/apps/gnu/linux/x86_64/6/lib64/pkgconfig:/usr/lib/pkgconfig:/usr/lib64/pkgconfig:/usr/share/pkgconfig:/lib/pkgconfig:/lib64/pkgconfig' Configured features: XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GSETTINGS NOTIFY ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE LIBOTF XFT ZLIB TOOLKIT_SCROLL_BARS GTK2 X11 MODULES Important settings: value of $LANG: en_US.UTF-8 value of $XMODIFIERS: @im=none locale-coding-system: utf-8-unix Major mode: Lisp Interaction Minor modes in effect: tooltip-mode: t global-eldoc-mode: t eldoc-mode: t electric-indent-mode: t mouse-wheel-mode: t tool-bar-mode: t menu-bar-mode: t file-name-shadow-mode: t global-font-lock-mode: t font-lock-mode: t blink-cursor-mode: t auto-composition-mode: t auto-encryption-mode: t auto-compression-mode: t line-number-mode: t transient-mark-mode: t Load-path shadows: None found. Features: (shadow sort mail-extr emacsbug message subr-x puny seq byte-opt gv bytecomp byte-compile cconv cl-loaddefs cl-lib dired dired-loaddefs format-spec rfc822 mml easymenu mml-sec password-cache epa derived epg epg-config gnus-util rmail rmail-loaddefs mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils elec-pair time-date mule-util tooltip eldoc electric uniquify ediff-hook vc-hooks lisp-float-type mwheel term/x-win x-win term/common-win x-dnd tool-bar dnd fontset image regexp-opt fringe tabulated-list replace newcomment text-mode elisp-mode lisp-mode prog-mode register page menu-bar rfn-eshadow isearch timer select scroll-bar mouse jit-lock font-lock syntax facemenu font-core term/tty-colors frame cl-generic cham georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean japanese eucjp-ms cp51932 hebrew greek romanian slovak czech european ethiopic indian cyrillic chinese composite charscript charprop case-table epa-hook jka-cmpr-hook help simple abbrev obarray minibuffer cl-preloaded nadvice loaddefs button faces cus-face macroexp files text-properties overlay sha1 md5 base64 format env code-pages mule custom widget hashtable-print-readable backquote dbusbind inotify dynamic-setting system-font-setting font-render-setting move-toolbar gtk x-toolkit x multi-tty make-network-process emacs) Memory information: ((conses 16 97100 8003) (symbols 48 20813 1) (miscs 40 46 119) (strings 32 28798 1799) (string-bytes 1 765072) (vectors 16 14942) (vector-slots 8 508712 6478) (floats 8 48 68) (intervals 56 245 0) (buffers 992 11) (heap 1024 29158 859)) -- Kaushal Modi