try to change the BLUETOOTH_DEVICE_INFO structure...
#include
Global Const $hDllBthProps = DllOpen("bthprops.cpl")
Func _BluetoothFindFirstDevice()
$tBLUETOOTH_DEVICE_SEARCH_PARAMS = DllStructCreate('DWORD;BOOL;BOOL;BOOL;BOOL;BOOL;BYTE;HANDLE')
DllStructSetData($tBLUETOOTH_DEVICE_SEARCH_PARAMS, 1 , DllStructGetSize($tBLUETOOTH_DEVICE_SEARCH_PARAMS))
DllStructSetData($tBLUETOOTH_DEVICE_SEARCH_PARAMS, 2 , False)
DllStructSetData($tBLUETOOTH_DEVICE_SEARCH_PARAMS, 3 , False)
DllStructSetData($tBLUETOOTH_DEVICE_SEARCH_PARAMS, 4 , True)
DllStructSetData($tBLUETOOTH_DEVICE_SEARCH_PARAMS, 5 , False)
DllStructSetData($tBLUETOOTH_DEVICE_SEARCH_PARAMS, 6 , True)
DllStructSetData($tBLUETOOTH_DEVICE_SEARCH_PARAMS, 7 , 30)
DllStructSetData($tBLUETOOTH_DEVICE_SEARCH_PARAMS, 8 , 0)
;$SYSTEMTIME=DllStructCreate("ushort wYear;ushort wMonth;ushort wDayOfWeek;ushort wDay;ushort wHour;ushort wMinute;ushort wSecond;ushort wMilliseconds")
;DllCall("Kernel32.dll","none","GetSystemTime","ptr",DllStructGetPtr($SYSTEMTIME))
$tBLUETOOTH_DEVICE_INFO = DllStructCreate('DWORD;UINT64;ULONG;BOOL;BOOL;BOOL;word[8];word[8];WCHAR[248]')
DllStructSetData($tBLUETOOTH_DEVICE_INFO,1,DllStructGetSize($tBLUETOOTH_DEVICE_INFO))
;DllStructSetData($tBLUETOOTH_DEVICE_INFO,7,DllStructGetPtr($SYSTEMTIME))
;DllStructSetData($tBLUETOOTH_DEVICE_INFO,8,DllStructGetPtr($SYSTEMTIME))
$RESULT = DllCall($hDllBthProps, "handle", "BluetoothFindFirstDevice", "struct*", $tBLUETOOTH_DEVICE_SEARCH_PARAMS, "struct*", $tBLUETOOTH_DEVICE_INFO)
msgbox(64, "", 'Result: ' & $RESULT[0] & @crlf & 'WinAPI Error: ' & _WinAPI_GetLastErrorMessage() & @crlf & 'Error: ' & @error)
EndFunc
_BluetoothFindFirstDevice()