Are shell scripts sensitive to encoding and line endings?

I am making an NW.js app on macOS, and want to run the app in dev modeby double-clicking on an icon.In the first step, I'm trying to make my shell script work.

Using VS Code on Windows (I wanted to gain time), I have created a run-nw file at the root of my project, containing this:

#!/bin/bashcd "src"npm installcd .../tools/nwjs-sdk-v0.17.3-osx-x64/nwjs.app/Contents/MacOS/nwjs "src" &

but I get this output:

$ sh ./run-nw: command not found  : No such file or directory  : command not found  : No such file or directory  Usage: npm <command>where <command> is one of:  (snip commands list)(snip npm help)npm@3.10.3 /usr/local/lib/node_modules/npm  : command not found  : No such file or directory  : command not found

Some things I don't understand.

• It seems that it takes empty lines as commands.In my editor (VS Code) I have tried to replace \r\n with \n(in case the \r creates problems) but it changes nothing.
• It seems that it doesn't find the folders(with or without the dirname instruction),or maybe it doesn't know about the cd command ?
• It seems that it doesn't understand the install argument to npm.
• The part that really weirds me out, is that it still runs the app(if I did an npm install manually)...

Not able to make it work properly, and suspecting something weird withthe file itself, I created a new one directly on the Mac, using vim this time.I entered the exact same instructions, and... now it works without anyissues.
A diff on the two files reveals exactly zero difference.

What can be the difference? What can make the first script not work? How can I find out?

Update

Following the accepted answer's recommendations, after the wrong lineendings came back, I checked multiple things.It turns out that since I copied my ~/.gitconfig from my Windowsmachine, I had autocrlf=true, so every time I modified the bashfile under Windows, it re-set the line endings to \r\n.
So, in addition to running dos2unix (which you will have toinstall using Homebrew on a Mac), if you're using Git, check your.gitconfig file.