Under gdb, just clicking on vCalendar meetings folder, it crashes, likely because of a division by zero: hread 1 "claws-mail" received signal SIGFPE, Arithmetic exception. 0x00007fffcc4edfa0 in build_day_view_header (start_date=0x1a2de00 "05/09/19", dw=0x205db70) at day-view.c:636 636 avail_d = avail_w / dw->StartDate_button_req.width; Full backtrace: (gdb) bt full #0 0x00007fffcc4edfa0 in build_day_view_header (start_date=0x1a2de00 "05/09/19", dw=0x205db70) at day-view.c:636 allocation = {x = 0, y = 0, width = 1016, height = 166} space_label = 0x17dbdd0 summaryview = <optimized out> avail_w = 996 hbox = <optimized out> label = <optimized out> avail_d = 0 #1 create_day_win (item=item@entry=0x1750710, tmdate=...) at day-view.c:895 dw = 0x205db70 start_date = 0x1a2de00 "05/09/19" #2 0x00007fffcc4dc49d in vcal_item_opened (item=0x1750710) at vcal_folder.c:326 tmdate = {tm_sec = 45, tm_min = 33, tm_hour = 10, tm_mday = 9, tm_mon = 4, tm_year = 119, tm_wday = 4, tm_yday = 128, tm_isdst = 1, tm_gmtoff = 7200, tm_zone = 0x11d85c0 "CEST"} t = 1557390825 #3 0x000000000057f75f in summary_show (summaryview=0xf3f800, item=item@entry=0x1750710) at summaryview.c:1275 ctree = 0xd88aa0 node = 0x0 mlist = 0x0 buf = <optimized out> is_refresh = 0 selected_msgnum = 0 displayed_msgnum = 0 cur = <optimized out> not_killed = <optimized out> hidden_removed = 0 start = {tv_sec = 1557390825, tv_usec = 583869} end = {tv_sec = 0, tv_usec = 13279392} diff = <optimized out> timing_name = 0x7117f4 "" __FUNCTION__ = "summary_show" #4 0x00000000004a4e34 in folderview_selected (ctree=0xd88520, row=0xcb0220, column=-1, folderview=0xfcc400) at folderview.c:2369 can_select = 0 opened = <optimized out> item = 0x1750710 buf = <optimized out> res = <optimized out> old_opened = 0xcaa0a0 start = {tv_sec = 1557390825, tv_usec = 492195} end = {tv_sec = 16965808, tv_usec = 140737288512712} diff = <optimized out> timing_name = 0x7117f4 "" __FUNCTION__ = "folderview_selected" #5 0x00007ffff4142f75 in g_closure_invoke () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0 No symbol table info available. #6 0x00007ffff4154f82 in ?? () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0 No symbol table info available. #7 0x00007ffff415dbdc in g_signal_emit_valist () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0 No symbol table info available. #8 0x00007ffff415dfbf in g_signal_emit () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0 No symbol table info available. #9 0x000000000063008c in gtk_cmctree_select (ctree=ctree@entry=0xd88520, node=0xcb0220) at gtkcmctree.c:3862 No locals. #10 0x00000000006305ba in real_unselect_all (clist=0xd88520) at gtkcmctree.c:2839 ctree = 0xd88520 node = <optimized out> list = <optimized out> #11 0x000000000064db24 in gtk_sctree_real_unselect_all (clist=0xd88520) at gtksctree.c:796 sctree = 0xd88520 should_freeze = 0 #12 0x000000000064bf66 in select_row (sctree=sctree@entry=0xd88520, row=61, col=0, state=<optimized out>, _node=_node@entry=0x0) at gtksctree.c:385 range = <optimized out> additive = 0 #13 0x000000000064e6ba in gtk_sctree_button_press (widget=<optimized out>, event=0x13935b0) at gtksctree.c:558 sctree = 0xd88520 clist = 0xd88520 on_row = 1 row = 61 col = 0 retval = 0 #14 0x00007ffff70e0aac in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0 No symbol table info available. #15 0x00007ffff4142f75 in g_closure_invoke () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0 No symbol table info available. #16 0x00007ffff415537d in ?? () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0 No symbol table info available. #17 0x00007ffff415d67f in g_signal_emit_valist () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0 No symbol table info available. #18 0x00007ffff415dfbf in g_signal_emit () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0 No symbol table info available. #19 0x00007ffff722d57c in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0 No symbol table info available. #20 0x00007ffff70ddb2e in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0 No symbol table info available. #21 0x00007ffff70dfbee in gtk_main_do_event () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0 No symbol table info available. #22 0x00007ffff6bf0e15 in ?? () from /usr/lib/x86_64-linux-gnu/libgdk-3.so.0 No symbol table info available. #23 0x00007ffff6c21ea2 in ?? () from /usr/lib/x86_64-linux-gnu/libgdk-3.so.0 No symbol table info available. #24 0x00007ffff3e697f7 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 No symbol table info available. #25 0x00007ffff3e69a60 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 No symbol table info available. #26 0x00007ffff3e69d82 in g_main_loop_run () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 No symbol table info available. #27 0x00007ffff70ded55 in gtk_main () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0 No symbol table info available. #28 0x000000000044c88c in main (argc=<optimized out>, argv=<optimized out>) at main.c:1634 connection = 0xb03748 error = 0x0 userrc = <optimized out> mainwin = 0xbf0250 folderview = 0xfcc400 icon = 0xc7e800 crash_file_present = <optimized out> num_folder_class = <optimized out> asked_for_migration = <optimized out> start_done = <optimized out> plug_list = <optimized out> never_ran = <optimized out> mainwin_shown = <optimized out> ret = <optimized out> start = {tv_sec = 1557390108, tv_usec = 425} end = {tv_sec = 1557390109, tv_usec = 847796} diff = {tv_sec = 1, tv_usec = 847371} timing_name = 0x67baf4 "startup" __FUNCTION__ = "main" (gdb)