Hello,
sorry for the late reply. We do not know the cause yet and could not reproduce it so far. Other users report that printing from AutoCAD to the PDF24 printer is very slow, see https://help.pdf24.org/en/?p=63892
Please first try it with the current version of PDF24 Creator. If AutoCAD still stops responding, please tell us your PDF24 Creator version, your Windows version (e.g. Windows 11 24H2) and your AutoCAD version, and whether AutoCAD stops when you select the PDF24 printer in the plot dialog or after you click OK.
On Windows 11 24H2 and later you can add a second, driverless PDF24 printer for comparison: PDF24 Settings > PDF Printer > plus button Install a PDF printer, type Windows Protected Print. Please note that the driverless printer only offers standard paper sizes and no custom sizes. If AutoCAD works with it, we know that the problem is related to the driver of the classic PDF24 printer. More about the two kinds of printers: https://creator.pdf24.org/manual/11/#63-classic-and-driverless-pdf-printers