'rapidstm32_make_rtw_hook.m' is a .m file provided by the board supplier to do whatever processing they want through the standard RTW hook file. From the message, it seems that it tries to change the current folder, which is not allowed. However, this is a warning. I suspect the current folder is still changed. Maybe later, when it tries to change the folder back using relative path, it encountered an error.
But this is just my guess. You can open 'rapidstm32_make_rtw_hook.m', go to its 'exit' hook call to see where and why it needs to change directory. You can try modifying the file to see if it makes a difference. Be sure to make a copy first as this file is not meant to be modified by end user. My recommendation would be contact the board supplier technical support to report the problem.
One more thing is to make sure your current working folder is the folder that contains your model. Some scripts use relative path to change folder and it will cause problem.