The X error (from comment #3) is:
#3 0x00007f5a769377f7 in g_log_structured (log_domain=0x7f5a7365304e <_gdk_wayland_display_utf8_to_string_target+270> "f\220I\213U\bH\215J\001I;M\020s\"I\213u", log_level=G_LOG_LEVEL_ERROR) at ../../../../glib/gmessages.c:1768 args = {{gp_offset = 48, fp_offset = 48, overflow_arg_area = 0x7ffde50913e8, reg_save_area = 0x7ffde50912d0}} buffer = "`\t\223\002\000\000\000\000\300\r\t\345\375\177\000\000\020\v\223\002\000\000\000\000\220\r\t\345\375\177\000\000\240\v\223\002\000\000\000\000`\r\t\345\375\177\000\000\360\t\223\002\000\000\000\000\060\r\t\345\375\177\000\000\200\n\223\002\000\000\000\000\000\r\t\345\375\177\000\000\000\000\000\000\000\000\000\000D\366\221vZ\177\000\000@\310\222\002\000\000\000\000\300\243R\002\000\000\000\000\200\254:\001\000\000\000\000\231\001\000\000\000\000\000\000\360\020\t\345\375\177\000\000P\022\t\345\375\177\000\000 z\222\002\000\000\000\000\000\224\221\002\000\000\000\000@7\351EZ\177\000\000\222T\302vZ\177\000\000\300\223fsZ\177\000\000\000\351\063o\366\363[%\000\000\000\000\000\000\000\000"... message_allocated = 0x118ebd0 "The program 'ubiquity' received an X Window System error.\nThis probably reflects a bug in the program.\nThe error was 'BadAccess (attempt to access private resource denied)'.\n (Details: serial 14686 e"... format = 0x1 <error: Cannot access memory at address 0x1> message = <optimized out> p = <optimized out> n_fields = 6 i = 6 stack_fields = {{key = 0x7f5a76982af1 "MESSAGE", value = 0x118ebd0, length = -1}, {key = 0x7f5a76982b04 "PRIORITY", value = 0x7f5a7697cc9a, length = -1}, {key = 0x7f5a76982b5e "GLIB_DOMAIN", value = 0x7f5a7365304e <_gdk_wayland_display_utf8_to_string_target+270>, length = -1}, {key = 0x7f5a736532a1 <data_source_dnd_finished+81> "\261%", value = 0x7f5a73671828 <__func__.67903+8>, length = -1}, {key = 0x7f5a73653281 <data_source_dnd_finished+49> "1\300\350\250\f\371\377H\213\065a\261%", value = 0x7f5a736712af, length = -1}, {key = 0x7f5a736532b3 <data_source_dnd_finished+99> "\017\037D", value = 0x7f5a73671f70 <__func__.66747+16>, length = -1}, {key = 0x0, value = 0x7ffde5090eb0, length = 140026516315808}, {key = 0x7f5a76c11192 <g_object_new_valist+258> "H\205\300H\211\301\017\204\312\003", value = 0x0, length = 0}, {key = 0x0, value = 0x7ffde5090eb0, length = 140026516315808}, {key = 0x7f5a76c11192 <g_object_new_valist+258> "H\205\300H\211\301\017\204\312\003", value = 0x7ffde5090eb0, length = 43252528}, {key = 0x293fb30 "\200\222\221\002", value = 0x7ffde5091000, length = 0}, {key = 0x0, value = 0x7ffde5090d00, length = 43190912}, {key = 0x2919280 "\002", value = 0x602c55ce0, length = 0}, {key = 0x0, value = 0x0, length = 0}, {key = 0x0, value = 0x0, length = 0}, {key = 0x0, value = 0x2932c50, length = 140728446029296}} fields = 0x7ffde5090d40 fields_allocated = 0x0 array = <optimized out>
The X error (from comment #3) is:
#3 0x00007f5a769377f7 in g_log_structured (log_domain= 0x7f5a7365304e <_gdk_wayland_ display_ utf8_to_ string_ target+ 270> "f\220I\ 213U\bH\ 215J\001I; M\020s\ "I\213u" , log_level= G_LOG_LEVEL_ ERROR) at ../../. ./../glib/ gmessages. c:1768 002\000\ 000\000\ 000\300\ r\t\345\ 375\177\ 000\000\ 020\v\223\ 002\000\ 000\000\ 000\220\ r\t\345\ 375\177\ 000\000\ 240\v\223\ 002\000\ 000\000\ 000`\r\ t\345\375\ 177\000\ 000\360\ t\223\002\ 000\000\ 000\000\ 060\r\t\ 345\375\ 177\000\ 000\200\ n\223\002\ 000\000\ 000\000\ 000\r\t\ 345\375\ 177\000\ 000\000\ 000\000\ 000\000\ 000\000\ 000D\366\ 221vZ\177\ 000\000@ \310\222\ 002\000\ 000\000\ 000\300\ 243R\002\ 000\000\ 000\000\ 200\254: \001\000\ 000\000\ 000\231\ 001\000\ 000\000\ 000\000\ 000\360\ 020\t\345\ 375\177\ 000\000P\ 022\t\345\ 375\177\ 000\000 z\222\002\ 000\000\ 000\000\ 000\224\ 221\002\ 000\000\ 000\000@ 7\351EZ\ 177\000\ 000\222T\ 302vZ\177\ 000\000\ 300\223fsZ\ 177\000\ 000\000\ 351\063o\ 366\363[ %\000\000\ 000\000\ 000\000\ 000\000" ...
message_ allocated = 0x118ebd0 "The program 'ubiquity' received an X Window System error.\nThis probably reflects a bug in the program.\nThe error was 'BadAccess (attempt to access private resource denied)'.\n (Details: serial 14686 e"...
stack_ fields = {{key = 0x7f5a76982af1 "MESSAGE", value = 0x118ebd0, length = -1}, {key = 0x7f5a76982b04 "PRIORITY", value = 0x7f5a7697cc9a, length = -1}, {key = 0x7f5a76982b5e "GLIB_DOMAIN", value = 0x7f5a7365304e <_gdk_wayland_ display_ utf8_to_ string_ target+ 270>, length = -1}, {key = 0x7f5a736532a1 <data_source_ dnd_finished+ 81> "\261%", value = 0x7f5a73671828 <__func__.67903+8>, length = -1}, {key = 0x7f5a73653281 <data_source_ dnd_finished+ 49> "1\300\ 350\250\ f\371\377H\ 213\065a\ 261%", value = 0x7f5a736712af, length = -1}, {key = 0x7f5a736532b3 <data_source_ dnd_finished+ 99> "\017\037D", value = 0x7f5a73671f70 <__func_ _.66747+ 16>, length = -1}, {key = 0x0, value = 0x7ffde5090eb0, length = 140026516315808}, {key = 0x7f5a76c11192 <g_object_ new_valist+ 258> "H\205\ 300H\211\ 301\017\ 204\312\ 003", value = 0x0, length = 0}, {key = 0x0, value = 0x7ffde5090eb0, length = 140026516315808}, {key = 0x7f5a76c11192 <g_object_ new_valist+ 258> "H\205\ 300H\211\ 301\017\ 204\312\ 003", value = 0x7ffde5090eb0, length = 43252528}, {key = 0x293fb30 "\200\222\221\002", value = 0x7ffde5091000, length = 0}, {key = 0x0, value = 0x7ffde5090d00, length = 43190912}, {key = 0x2919280 "\002", value = 0x602c55ce0, length = 0}, {key = 0x0, value = 0x0, length = 0}, {key = 0x0, value = 0x0, length = 0}, {key = 0x0, value = 0x2932c50, length = 140728446029296}}
fields_ allocated = 0x0
args = {{gp_offset = 48, fp_offset = 48, overflow_arg_area = 0x7ffde50913e8, reg_save_area = 0x7ffde50912d0}}
buffer = "`\t\223\
format = 0x1 <error: Cannot access memory at address 0x1>
message = <optimized out>
p = <optimized out>
n_fields = 6
i = 6
fields = 0x7ffde5090d40
array = <optimized out>