211014  9:30:02 [ERROR] mysqld got exception 0xc0000005 ;
This could be because you hit a bug. It is also possible that this binary
or one of the libraries it was linked against is corrupt, improperly built,
or misconfigured. This error can also be caused by malfunctioning hardware.

To report this bug, see https://mariadb.com/kb/en/reporting-bugs

We will try our best to scrape up some info that will hopefully help
diagnose the problem, but since we have already crashed, 
something is definitely wrong and this may fail.

Server version: 10.6.3-MariaDB
key_buffer_size=10485760
read_buffer_size=131072
max_used_connections=6
max_threads=65537
thread_count=3
It is possible that mysqld could use up to 
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 15718 K  bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

Thread pointer: 0x20599984d88
Attempting backtrace. You can use the following information to find out
where mysqld died. If you see no messages after this, something went
terribly wrong...
server.dll!Item_cond_and::mark_as_condition_AND_part()[item_cmpfunc.cc:5388]
server.dll!setup_conds()[sql_base.cc:8444]
server.dll!setup_without_group()[sql_select.cc:833]
server.dll!JOIN::prepare()[sql_select.cc:1401]
server.dll!st_select_lex_unit::prepare_join()[sql_union.cc:1090]
server.dll!st_select_lex_unit::prepare()[sql_union.cc:1483]
server.dll!mysql_derived_prepare()[sql_derived.cc:855]
server.dll!mysql_handle_single_derived()[sql_derived.cc:200]
server.dll!TABLE_LIST::handle_derived()[table.cc:9205]
server.dll!st_select_lex::handle_derived()[sql_lex.cc:4996]
server.dll!TABLE_LIST::handle_derived()[table.cc:9202]
server.dll!st_select_lex::handle_derived()[sql_lex.cc:4996]
server.dll!JOIN::prepare()[sql_select.cc:1299]
server.dll!st_select_lex_unit::prepare_join()[sql_union.cc:1090]
server.dll!st_select_lex_unit::prepare()[sql_union.cc:1569]
server.dll!mysql_union()[sql_union.cc:39]
server.dll!handle_select()[sql_select.cc:560]
server.dll!execute_sqlcom_select()[sql_parse.cc:6252]
server.dll!mysql_execute_command()[sql_parse.cc:3947]
server.dll!sp_instr_stmt::exec_core()[sp_head.cc:3774]
server.dll!sp_lex_keeper::reset_lex_and_exec_core()[sp_head.cc:3499]
server.dll!sp_instr_stmt::execute()[sp_head.cc:3678]
server.dll!sp_head::execute()[sp_head.cc:1437]
server.dll!sp_head::execute_procedure()[sp_head.cc:2451]
server.dll!do_execute_sp()[sql_parse.cc:3026]
server.dll!Sql_cmd_call::execute()[sql_parse.cc:3272]
server.dll!mysql_execute_command()[sql_parse.cc:6005]
server.dll!mysql_parse()[sql_parse.cc:8030]
server.dll!dispatch_command()[sql_parse.cc:1898]
server.dll!do_command()[sql_parse.cc:1404]
server.dll!threadpool_process_request()[threadpool_common.cc:395]
server.dll!tp_callback()[threadpool_common.cc:203]
KERNEL32.DLL!TermsrvSetKeySecurity()
ntdll.dll!RtlEqualUnicodeString()
ntdll.dll!TpReleaseCleanupGroupMembers()
KERNEL32.DLL!BaseThreadInitThunk()
ntdll.dll!RtlUserThreadStart()

Trying to get some variables.
Some pointers may be invalid and cause the dump to abort.
Query (0x205a897a110): WITH ctePersonalTag AS (

		SELECT

			a.auftrag_id,

			CONCAT_WS(': ',

				IFNULL(f.kurztext_1, f.text_1),

				CASE WHEN LENGTH(a.text_1) > 30 THEN CONCAT(LEFT(a.text_1,30), '...') ELSE a.text_1 END

			) AS mandat,

			IFNULL(mandatsleiter.kurztext_1, '(nobody)') AS mandatsleiter,

			CONCAT_WS(' ',

				personal.kurztext_1,

				CASE

					WHEN zeit_eintrag.zeit_eintrag_art_id <> personal.zeit_eintrag_art_id THEN CONCAT('(als ', zeit_eintrag_art.text_1, ')')

					ELSE NULL

				END

			) AS mitarbeiter,

			personal.personal_id,

			IFNULL(mandatsleiter.login_user, 'nobody') AS mandatsleiter_login_user,

			zeit_eintrag_art.text_1 AS zeit_eintrag_art,

			zeit_eintrag.zeit_eintrag_art_id,

			IFNULL(zeit_eintrag.eintrag_dat, CAST(zeit_eintrag.startzeit AS DATE)) AS eintrag_dat,

			CAST(SUM(IFNULL(zeit_eintrag.zeit, (UNIX_TIMESTAMP(zeit_eintrag.endzeit)-UNIX_TIMESTAMP(zeit_eintrag.startzeit))/60/60)) AS DECIMAL(18,2)) AS stunden,

			CAST(ROUND(SUM(IFNULL(zeit_eintrag.zeit, (UNIX_TIMESTAMP(zeit_eintrag.endzeit)-UNIX_TIMESTAMP(zeit_eintrag.startzeit))/60/60)) * IFNULL(auftrag_satz.stundensatz, zeit_eintrag_art.stundensatz),2) AS DECIMAL(18,2)) AS kosten,

			MIN(CASE WHEN zeit_eintrag.zeit IS NOT NULL THEN zeit_eintrag.eintrag_dat ELSE zeit_eintrag.startzeit END) AS min_dat,

			MAX(CASE WHEN zeit_eintrag.zeit IS NOT NULL THEN zeit_eintrag.eintrag_dat ELSE zeit_eintrag.startzeit END) AS max_dat,

			DATE_FORMAT( NAME_CONST('vormonat_ende',DATE'2021-09-30'), '%b') AS text_vormonat,

			DATE_FORMAT( NAME_CONST('monat_ende',DATE'2021-10-31'), '%b') AS text_monat,

			CONCAT_WS(', ', a.modell, CASE WHEN a.pauschale IS NULL THEN NULL ELSE CONCAT(a.periodizitaet, ' mo') END) AS modell,

			a.pauschale

		FROM

			auftrag a 

			LEFT JOIN zeit_eintrag ON a.auftrag_id = zeit_eintrag.auftrag_id

			LEFT JOIN personal mandatsleiter ON mandatsleiter.personal_id = a.personal_id

			LEFT JOIN firma f ON f.firma_id = a.gegenpartei_firma_id

			JOIN auftrag_art ON auftrag_art.auftrag_art_id = a.auftrag_art_id

			JOIN auftrag_status ON auftrag_status.auftrag_status_id = a.auftrag_status_id

			LEFT JOIN personal ON personal.personal_id = zeit_eintrag.personal_id

			LEFT JOIN zeit_eintrag_art ON zeit_eintrag_art.zeit_eintrag_art_id = IFNULL(zeit_eintrag.zeit_eintrag_art_id, personal.zeit_eintrag_art_id)

			LEFT JOIN auftrag_satz 

				ON auftrag_satz.auftrag_id = zeit_eintrag.auftrag_id

				AND auftrag_satz.personal_id = zeit_eintrag.personal_id

				AND auftrag_satz.zeit_eintrag_art_id = zeit_eintrag_art.zeit_eintrag_art_id

		WHERE

			a.arbeit_jn <> 0

			AND auftrag_status.zeiterfassung_jn <> 0

			AND has_auftrag_right(a.auftrag_id)

		GROUP BY

			a.auftrag_id,

			zeit_eintrag.zeit_eintrag_art_id,

			IFNULL(zeit_eintrag.eintrag_dat, CAST(zeit_eintrag.startzeit AS DATE)),

			zeit_eintrag.personal_id

	),

  -- ;

  

  -- WITH

	ctePersonal AS (

		SELECT

			pt.auftrag_id,

			pt.mandat,

			pt.mandatsleiter,

			pt.mandatsleiter_login_user,

			pt.mitarbeiter,

			pt.zeit_eintrag_art,

			SUM(CASE WHEN eintrag_dat BETWEEN  NAME_CONST('vormonat_start',DATE'2021-09-01') AND  NAME_CONST('vormonat_ende',DATE'2021-09-30') THEN pt.stunden ELSE NULL END) AS stunden_vormonat,

			SUM(CASE WHEN eintrag_dat BETWEEN  NAME_CONST('vormonat_start',DATE'2021-09-01') AND  NAME_CONST('vormonat_ende',DATE'2021-09-30') THEN pt.kosten ELSE NULL END) AS kosten_vormonat,

			SUM(CASE WHEN eintrag_dat BETWEEN  NAME_CONST('monat_start',DATE'2021-10-01') AND  NAME_CONST('monat_ende',DATE'2021-10-31') THEN pt.stunden ELSE NULL END) AS stunden_monat,

			SUM(CASE WHEN eintrag_dat BETWEEN  NAME_CONST('monat_start',DATE'2021-10-01') AND  NAME_CONST('monat_ende',DATE'2021-10-31') THEN pt.kosten ELSE NULL END) AS kosten_monat,

			SUM(pt.stunden) AS stunden_total,

			SUM(pt.kosten) AS kosten_total,

			MIN(pt.eintrag_dat) AS min_dat,

			MAX(pt.eintrag_dat) AS max_dat,

			text_vormonat,

			text_monat,

			modell,

			pauschale

		FROM

			ctePersonalTag pt

		GROUP BY

			pt.auftrag_id,

			pt.personal_id,

			pt.zeit_eintrag_art

	)

	

	-- Total pro Auftrag

	SELECT

		auftrag_id,

		SUM(kosten_total) AS sortier_total,

		mandat,

		1 AS lvl,

		'TOTAL' AS mitarbeiter,

		NULL AS zeit_eintrag_art,

		SUM(stunden_vormonat) AS stunden_vormonat,

		SUM(kosten_vormonat) AS kosten_vormonat,

		SUM(stunden_monat) AS stunden_monat,

		SUM(kosten_monat) AS kosten_monat,

		SUM(stunden_total) AS stunden_total,

		SUM(kosten_total) AS kosten_total,

		CONCAT_WS(' - ',

			DATE_FORMAT(MIN(min_dat), '%d.%m.'),

			DATE_FORMAT(MAX(max_dat), '%d.%m.')

		) AS periode,

		text_vormonat,

		text_monat,

		mandatsleiter,

		mandatsleiter_login_user,

		modell,

		pauschale

	FROM

		ctePersonal

	GROUP BY

		auftrag_id

		

	UNION ALL

	

	-- Total pro Mitarbeiter

	SELECT

		p1.auftrag_id,

		(SELECT SUM(kosten_total) FROM ctePersonal p2 WHERE p2.auftrag_id = p1.auftrag_id) AS sortier_total,

		mandat,

		2 AS lvl,

		mitarbeiter,

		zeit_eintrag_art,

		stunden_vormonat,

		kosten_vormonat,

		stunden_monat,

		kosten_monat,

		stunden_total,

		kosten_total,

		CONCAT_WS(' - ',

			DATE_FORMAT(min_dat, '%d.%m.'),

			DATE_FORMAT(max_dat, '%d.%m.')

		) AS periode,

		text_vormonat,

		text_monat,

		mandatsleiter,

		mandatsleiter_login_user,

		NULL,

		NULL

	FROM 

		ctePersonal p1



	UNION ALL



	-- Gesamttotal 

	SELECT

		NULL AS auftrag_id,

		SUM(kosten_total) AS sortier_total,

		CONCAT_WS(' ', gettc('TOTAL', @@lc_time_names), mandatsleiter) AS mandat,

		0 AS lvl,

		CONCAT_WS(' ', gettc('TOTAL', @@lc_time_names), mandatsleiter) AS Staff,

		NULL AS zeit_eintrag_art,

		SUM(stunden_vormonat) AS stunden_vormonat,

		SUM(kosten_vormonat) AS kosten_vormonat,

		SUM(stunden_monat) AS stunden_monat,

		SUM(kosten_monat) AS kosten_monat,

		SUM(stunden_total) AS stunden_total,

		SUM(kosten_total) AS kosten_total,

		CONCAT_WS(' - ',

			DATE_FORMAT(MIN(min_dat), '%d.%m.'),

			DATE_FORMAT(MAX(max_dat), '%d.%m.')

		) AS periode,

		text_vormonat,

		text_monat,

		mandatsleiter,

		mandatsleiter_login_user,

		NULL,

		NULL

	FROM 

		ctePersonal

	GROUP BY

		mandatsleiter

		

	ORDER BY

		CASE

			WHEN mandatsleiter_login_user = db_user() THEN 1 

			ELSE 2 

		END,

		mandatsleiter,

		sortier_total DESC,

		auftrag_id,

		lvl,

		kosten_total DESC
Connection ID (thread ID): 57241
Status: NOT_KILLED

Optimizer switch: index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on,not_null_range_scan=off

The manual page at https://mariadb.com/kb/en/how-to-produce-a-full-stack-trace-for-mysqld/ contains
information that should help you find out what is causing the crash.
Writing a core file at C:\Program Files\MariaDB 10.5\data\