I need to use textwrangler for a school assignment...do not know how to update it so it will be compatible. How do I do that?

Text Wrangler was dropped, but the same developer provides a free version of BBEdit that is the same except in name...

https://www.barebones.com/products/bbedit/

It is not compatible with macOS High Sierra 10.13 or later.

Contrary to what BareBones says on its website, Textwrangler is compatible with High Sierra. I've been running it on multiple Macs on High Sierra for years. Currently using Textwrangler 5.5.2 on High Sierra 10.13.6. Have never had any problems with it.

Unfortunately it's a moot point because you can't get it any more from either the App Store or BareBones.

Although historically I used TextWrangler v5.5.2, when BareBones retired it, I replaced it with BBEdit sufficiently long ago that I cannot remember if I ever had TW installed on High Sierra.

TextWrangler has been retired by Bare Bones Software for several years now, and ran on macOS, not iOS. It is not compatible with macOS High Sierra 10.13 or later.

Use the BBEdit 13 trial, which will become free like TextWrangler was, when the BBEdit trial ends. BBEdit 13 requires macOS 10.14.2 (though 10.14.6 is recommended) or later.

See here for macOS compatibility, and older versions of BBEdit if you are not on Mojave yet.

I've been using BBEdit for awhile now, but today when I tried to edit a file, it wouldn't let me save the file to a different name.

I did find this - but I never got the error message and when I go to the Privacy page - BBEdit isn’t there.

https://www.barebones.com/support/bbedit/ODBAutomationError.html

Using BBEdit 13.5 and Catalina 10.15.6

Thanks much.

If you're working with "plain text" files, there are other options and tools available, too.

That might be other text editors or command-line text editors, or an IDE of some sort if you're programming.

If you'd like to discuss that, posting a few more details on the goal might help with a different (better?) solution.

But as stated above, whatever document you're reading that lists TextWrangler is getting a little dated.