Ok perhaps this is more helpfull? Debugger entered--Lisp error: (wrong-type-argument number-or-marker-p nil) notmuch-search-show-result("tags") byte-code("\304\305\"\203\306 !\307=\203\310\202Q\303\202Q\304\311\"\203D\312 !\304\313\"\2030\310\202@\304\314\"\203<\315\202@\316!\210)\202Q\304\317\"\203Q\320 !\210\310\304\207" [notmuch-search-process-state notmuch-search-json-parser done result memql (begin) notmuch-json-begin-compound retry t (result) notmuch-json-read (retry) (end) end notmuch-search-show-result (end) notmuch-json-eof] 3) notmuch-search-process-filter(#<process notmuch-search> ", \"tags\": []},\nA Xapian exception occurred performing query: The revision being read has been discarded - you should call Xapian::Database::reopen() and retry the operation\nQuery string was: thread:0000000000020a59\n{\"thread\": \"000000000001fd19\", \"timestamp\": 0, \"date_relative\": \"1970-01-01\", \"matched\": 0, \"total\": 0, \"authors\": \"\", \"subject\": \"\", \"tags\": []},\nA Xapian exception occurred performing query: The revision being read has been discarded - you should call Xapian::Database::reopen() and retry the operation\nQuery string was: thread:0000000000020a57\n{\"thread\": \"0000000000020a59\", \"timestamp\": 0, \"date_relative\": \"1970-01-01\", \"matched\": 0, \"total\": 0, \"authors\": \"\", \"subject\": \"\", \"tags\": []},\nA Xapian exception occurred performing query: The revision being read has been discarded - you should call Xapian::Database::reopen() and retry the operation\nQuery string was: thread:0000000000020a57\n{\"thread\": \"0000000000020a57\", \"timestamp\": 0, \"date_relative\": \"1970-01-01\", \"matched\": 0, \"total\": 0, \"authors\": ") recursive-edit() debug(error (error "A Xapian exception occurred opening database: Unable to get write lock on /Users/bart/mail/.notmuch/xapian: already locked")) ad-Orig-signal(error ("A Xapian exception occurred opening database: Unable to get write lock on /Users/bart/mail/.notmuch/xapian: already locked")) signal(error ("A Xapian exception occurred opening database: Unable to get write lock on /Users/bart/mail/.notmuch/xapian: already locked")) ad-Orig-error("A Xapian exception occurred opening database: Unable to get write lock on /Users/bart/mail/.notmuch/xapian: already locked") apply(ad-Orig-error "A Xapian exception occurred opening database: Unable to get write lock on /Users/bart/mail/.notmuch/xapian: already locked") error("A Xapian exception occurred opening database: Unable to get write lock on /Users/bart/mail/.notmuch/xapian: already locked") notmuch-call-notmuch-process("tag" "-inbox" "--" "thread:0000000000022288") apply(notmuch-call-notmuch-process "tag" ("-inbox" "--" "thread:0000000000022288")) notmuch-tag("thread:0000000000022288" ("-inbox")) notmuch-search-tag-region(202 202 ("-inbox")) notmuch-search-tag(("-inbox")) ad-Orig-notmuch-search-archive-thread() notmuch-search-archive-thread() call-interactively(notmuch-search-archive-thread nil nil) recursive-edit() debug(error (error "A Xapian exception occurred opening database: Unable to get write lock on /Users/bart/mail/.notmuch/xapian: already locked")) ad-Orig-signal(error ("A Xapian exception occurred opening database: Unable to get write lock on /Users/bart/mail/.notmuch/xapian: already locked")) signal(error ("A Xapian exception occurred opening database: Unable to get write lock on /Users/bart/mail/.notmuch/xapian: already locked")) ad-Orig-error("A Xapian exception occurred opening database: Unable to get write lock on /Users/bart/mail/.notmuch/xapian: already locked") apply(ad-Orig-error "A Xapian exception occurred opening database: Unable to get write lock on /Users/bart/mail/.notmuch/xapian: already locked") Kind regards Bart