Put the attached 3 files, `f1.cpp`, `f2.cpp` and `TAGS` into an empty folder. Do: 1) find-file f1.cpp (C-x C-f) 2) tags-query-replace ITracks JTracks There are 4 occurrences that are changed 3) tags-query-replace JTracks ITracks There are 2 occurrences that are changed, and it reports "Replaced 0 occurrences" It should have found the remaining 2 occurrences and the reported number of 0 is wrong. Hope you can reproduce this. In GNU Emacs 27.2 (build 1, x86_64-w64-mingw32) of 2021-03-26 built on CIRROCUMULUS Repository revision: deef5efafb70f4b171265b896505b92b6eef24e6 Repository branch: HEAD Windowing system distributor 'Microsoft Corp.', version 10.0.19042 System Description: Microsoft Windows 10 Enterprise (v10.0.2009.19042.928) Recent messages: Replaced 2 occurrences Scanning file d:/Bob/Temp/emacs/f2.cpp... Mark set Replaced 2 occurrences user-error: All files processed Mark set Replaced 2 occurrences Scanning file d:/Bob/Temp/emacs/f2.cpp... Mark set Replaced 0 occurrences Configured using: 'configure --without-dbus --host=x86_64-w64-mingw32 --without-compress-install 'CFLAGS=-O2 -static'' Configured features: XPM JPEG TIFF GIF PNG RSVG SOUND NOTIFY W32NOTIFY ACL GNUTLS LIBXML2 HARFBUZZ ZLIB TOOLKIT_SCROLL_BARS MODULES THREADS JSON PDUMPER LCMS2 GMP Important settings: value of $LANG: ENU locale-coding-system: cp1252 Major mode: C++//la Minor modes in effect: shell-dirtrack-mode: t show-paren-mode: t tooltip-mode: t global-eldoc-mode: t electric-indent-mode: t mouse-wheel-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 abbrev-mode: t Load-path shadows: d:/Bob/.emacs.d/elpa/verilog-mode-2020.6.27.14326051/verilog-mode hides c:/Program Files/Emacs 27.2/x86_64/share/emacs/27.2/lisp/progmodes/verilog-mode Features: (shadow sort mail-extr emacsbug message rmc puny format-spec rfc822 mml mml-sec epa epg epg-config gnus-util rmail rmail-loaddefs text-property-search mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils thingatpt etags fileloop generator xref project dired dired-loaddefs pcmpl-unix time-date web-mode advice derived edmacro kmacro shell pcomplete comint ansi-color ring printing ps-print ps-print-loaddefs ps-def lpr paren cc-mode cc-fonts cc-guess cc-menus cc-cmds cc-styles cc-align cc-engine cc-vars cc-defs finder-inf tex-site info package easymenu browse-url url-handlers url-parse auth-source cl-seq eieio eieio-core cl-macs eieio-loaddefs password-cache json subr-x map url-vars seq byte-opt gv bytecomp byte-compile cconv cl-loaddefs cl-lib tooltip eldoc electric uniquify ediff-hook vc-hooks lisp-float-type mwheel dos-w32 ls-lisp disp-table term/w32-win w32-win w32-vars term/common-win tool-bar dnd fontset image regexp-opt fringe tabulated-list replace newcomment text-mode elisp-mode lisp-mode prog-mode register page tab-bar menu-bar rfn-eshadow isearch timer select scroll-bar mouse jit-lock font-lock syntax facemenu font-core term/tty-colors frame minibuffer 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 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 threads w32notify w32 lcms2 multi-tty make-network-process emacs) Memory information: ((conses 16 174942 7392) (symbols 48 13957 1) (strings 32 45787 2201) (string-bytes 1 1506192) (vectors 16 19753) (vector-slots 8 248280 10026) (floats 8 286 53) (intervals 56 676 10) (buffers 1000 18))