DOS uses a carriage return (^M) with a line feed therefore linux system confused and thinks the script should be executed by /bin/bash^M which doesn’t exist.
Solution:
Option 1:
Install dos2unix and convert the file
dos2unix myscript.sh
Option 2:
vi and vim will convert line endings when you specify the file format.
vi myscript.sh
Hit ESC to enter command mode where you can set the format and save your changes.
:set fileformat=unix
:x!
Option 3:
sed is handy for cleaning up things like this from the command line.
sed -i 's/r//' myscript.sh