Hi, First, I apologize if my English isn't perfect. After upgrading my MariaDB server from version 10.6.18 to 10.6.19. I encountered an issue. When I execute a "SELECT ... FROM ( SELECT ... ) x WHERE x.colume1 .." statement, the server returns the error: "ERROR 2013 (HY000): Lost connection to server during query." I checked the `/var/log/messages` and found this message: "mariadb.service: Main process exited, code=killed, status=11/SEGV.". I used core dumping to investigate further and found that the stack frame count reaches #12171. The error at #0 is "... Item::build_clone ... at /usr/src/debug/MariaDB-/src_0/sql/item.h:1928". The previous stack frames keep repeating two frames: #1 Item_func_case_simple::do_build_clone ... at /usr/src/debug/MariaDB-/src_0/sql/item_cmpfunc.h:2448 #2 ... Item::build_clone ... at /usr/src/debug/MariaDB-/src_0/sql/item.h:1928 My OS is Rocky Linux 8.10. The MariaDB server versions where I encountered this issue are 10.6.19 and 10.11.9. The MariaDB server version without issues is 10.6.18. Has anyone else encountered this problem? Thanks in advance for any help.