Windows11 64bit, visual studio 2022, MariaDB 10.6\bin\mysql.exe Ver 15.1 Distrib 10.6.5-MariaDB, for Win64 (AMD64), source revision 109fc67d4da46d52d2a96528eaea3b0ef6275692

are you installing it with CREATE AGGREGATE FUNCTION ?
please, show the complete SQL script that together with the sample code reproduces the bug.

generally aggregate UDF functions work on Windows, there's an aggregate UDF in the udf_example.c and it's tested in our test suite which is run regularly in our CI, also on Windows (e.g. here)

CREATE FUNCTION ta_ema RETURNS REAL SONAME 'lib_mysqludf_ta.dll';
CREATE FUNCTION ta_max RETURNS REAL SONAME 'lib_mysqludf_ta.dll';
CREATE FUNCTION ta_min RETURNS REAL SONAME 'lib_mysqludf_ta.dll';
CREATE FUNCTION ta_previous RETURNS REAL SONAME 'lib_mysqludf_ta.dll';
CREATE FUNCTION ta_rsi RETURNS REAL SONAME 'lib_mysqludf_ta.dll';
CREATE FUNCTION ta_sma RETURNS REAL SONAME 'lib_mysqludf_ta.dll';
CREATE FUNCTION ta_stddevp RETURNS REAL SONAME 'lib_mysqludf_ta.dll';
CREATE FUNCTION ta_sum RETURNS REAL SONAME 'lib_mysqludf_ta.dll';
CREATE FUNCTION ta_tr RETURNS REAL SONAME 'lib_mysqludf_ta.dll';
CREATE FUNCTION ta_sma_win RETURNS REAL SONAME 'lib_mysqludf_ta.dll';
CREATE FUNCTION ta_rsi_win RETURNS REAL SONAME 'lib_mysqludf_ta.dll';
CREATE FUNCTION ta_atr_win RETURNS REAL SONAME 'lib_mysqludf_ta.dll';
CREATE FUNCTION ta_tr_win RETURNS REAL SONAME 'lib_mysqludf_ta.dll';

DROP FUNCTION IF EXISTS ta_ema;
DROP FUNCTION IF EXISTS ta_max;
DROP FUNCTION IF EXISTS ta_min;
DROP FUNCTION IF EXISTS ta_previous;
DROP FUNCTION IF EXISTS ta_rsi;
DROP FUNCTION IF EXISTS ta_sma;
DROP FUNCTION IF EXISTS ta_stddevp;
DROP FUNCTION IF EXISTS ta_sum;
DROP FUNCTION IF EXISTS ta_tr;
DROP FUNCTION IF EXISTS ta_sma_win;
DROP FUNCTION IF EXISTS ta_rsi_win;
DROP FUNCTION IF EXISTS ta_atr_win;
DROP FUNCTION IF EXISTS ta_tr_win;

possibly, the MariaDB not fully compatible with standard dll build/entry point.
please provide windows compilable source code with visual studio. not your half made lansi based code.

Can you please paste result of mysql.func table?

"name" "ret" "dl" "type"
"ta_ema" "1" "lib_mysqludf_ta.dll" "function"
"ta_max" "1" "lib_mysqludf_ta.dll" "function"
"ta_min" "1" "lib_mysqludf_ta.dll" "function"
"ta_previous" "1" "lib_mysqludf_ta.dll" "function"
"ta_rsi" "1" "lib_mysqludf_ta.dll" "function"
"ta_sma" "1" "lib_mysqludf_ta.dll" "function"
"ta_stddevp" "1" "lib_mysqludf_ta.dll" "function"
"ta_sum" "1" "lib_mysqludf_ta.dll" "function"
"ta_tr" "1" "lib_mysqludf_ta.dll" "function"
"ta_sma_win" "1" "lib_mysqludf_ta.dll" "function"
"ta_rsi_win" "1" "lib_mysqludf_ta.dll" "function"
"ta_atr_win" "1" "lib_mysqludf_ta.dll" "function"
"ta_tr_win" "1" "lib_mysqludf_ta.dll" "function"

does not '__declspec(dllexport) void ta_tr_win_clear(UDF_INIT *initid, char *is_null, char *error)' this prototype of dll entry not working with the server?

• • again, the normal simple series udf working great.

npdmailing@gmail.com, that's what I said in my first comment, you must use

CREATE AGGREGATE FUNCTION ta_tr_win RETURNS REAL SONAME 'lib_mysqludf_ta.dll';

note the keyword AGGREGATE

Shame me. Thanks.
issue resolved.
by the way,
where the location that keyword mentioned that mariaDb documents?

In CREATE FUNCTION statement

Holy....that isn't fair
cannot imagin/map that the normal function's option can be UDF things to applicate.
You guy must improve the udf section for aggregate keyword
to prevent spending whole daytime with pain without gain.

thanks.

cheers.