Question about TEAC W-1200

The problem almost certainly has to do with the fact that it is a USB 2.0 device. There are several reports on the internet about USB problems with Macbooks, old and new.
Before you can use the software, you must first make sure that the driver for the tape deck is installed correctly.
You can check this in the system information. If the tape deck is plugged in, it should appear there, if you unplug it, it should disappear again. If it does not disappear or does not appear at all, there is something wrong with the recognition or driver installation. The driver is integrated in macOS and should be installed automatically.
You don't have to use this software, you can use any software that can record audio.
How did you connect the cassette deck; does your Macbook have USB-A or do you use an adapter, etc.?
Will a USB keyboard, USB mouse, etc. work on the same port?
What might help is to use a higher quality USB 3.0 hub with power supply to connect the tape deck.
Can you still update the macOS?

Thank you very much for this chat!

I too thought I couldn't connect the Teac W 1200 to my Windows laptop (Lenovo, approx. 3 years old, Windows 10).

Thanks to the above hint that the deck appears as a sound card then got me further. As a user who has been used to Windows for decades, I always expected the Windows Explorer to pop up after plugging in the (printer!) USB cable, where the deck should then be visible as an added drive. However, it will never appear that way.

You can simply start Audacity and click on the red recording button there, and the curve graphics of the music now treated as a file will appear.

By the way, I have updated Audacity, currently version 3.2. You can recognise or set the "Input" in the "Audio Setup" under "Recording Device", where "USB Audio CODEC" was already set for me (as long as the USB cable of the deck that was switched on was plugged in.

The deck can then be found in the device manager under "Audio inputs and outputs".

Have fun, the thing is really working!

Dear Benedikt57. Thank you for your enquiry. Unfortunately, we are not familiar with MAC and therefore cannot help you.