how to read file.m?

I installed the new version of Matlab R2019b on Windows 10, and then I uninstalled the old version of Matlab R2016b, but when it finished the unistall, I can't open files with .m extention, and also when I save new codes using Matlab R2019. Where is the problem?

[Image Analyst]

Attach one of the m-files that you say R2019b cannot read. Can you open it with any other program, like notepad or Word?

[Enrica Brunetti]

Yes, I can open them with notepad

[Sai Bhargav Avula]

Please explain, what happens if you try to open the file. Do you get an error message? Also as suggested by Image Analyst try attaching a file.

[Walter Roberson]

https://www.mathworks.com/matlabcentral/fileexchange/51165-matlab-file-association-fix