The kernel for file.ipynb appears to have died. it will restart automatically

Hello there!

I am new to coding with jupyter notebook via anaconda navigator and anaconda prompt.

I used the prompt to add r and bash kernel.
Then I realised my notebook was not working properly again because it kept returning the message that “the kernel for file.ipynb (this is my file path in notebook) appears to have died. it will restart automatically”.

I tried to removed the r and bash kernels using anaconda prompt command lines, but these kernels are still present when I checked my list of kernels using ‘jupyter kernelspec list’.

I have uninstall and reinstall my anaconda several times, but nothing has changed.

I don’t know but I am sure the kernel has died message is related to these newly added kernels.

Please can someone help me?