Fix incorrect MIME/Content-Type for JavaScript on misconfigured Windows systems

[ghost]

Problem

Tornado serves JavaScript files with Content-Type: text/plain, which causes the browser to reject loading the JavaScript, due to Strict MIME checking enabled in the last version. This problem appears to manifest only on Windows hosted notebooks.

Solution

Similar to the CSS fix, add in a mimetypes override for .js files

closes #4467

[raeperd]

thanks! it works very well now!
I love you!

[ejmoya]

In w10 I have the same problem but it does not solve only with this. To solve it, I went to the directory "AppData\Local\Programs\Python\Python37\Lib\site-packages\notebook\templates" and edit the file "page.html" on line 18, changing the double quotes with single quotes.
Before:
<script src="{{static_url("components/es6-promise/promise.min.js")}}" type="text/javascript" charset="utf-8"></script>

After:
<script src="{{static_url('components/es6-promise/promise.min.js')}}" type="text/javascript" charset="utf-8"></script>

[lovettchris]

I had the blank page problem today, and this PR fixed it, thanks. Just had to do CTRL+F5 to force refresh and my Jupyter notebooks are back in business. Thanks!

[AnMa12]

I had the blank page problem today, and this PR fixed it, thanks. Just had to do CTRL+F5 to force refresh and my Jupyter notebooks are back in business. Thanks!

Thank you sir!

[ghost]

Thank you so much for fixing this, really hope this is merged soon.

[ghernie]

Thanks a lot mate !! It solved my MINE issue 👍

[deepandas11]

How to use this?

[BLGAmazingJ]

Thx^_^
Problem fixed.

[BLGAmazingJ]

How to use this?

You need to locate noteapp.py and override that part.

[gaborvecsei]

Thanks for the fix! ❤️

[kzq666666]

I am still confused about the details of solution

[matt-bernhardt]

This sounds like it would solve the problem I've had when starting to work with Jupyter, but I'm not sure how to check out this branch (via pip) to confirm this.

I'm trying to use Jupyter with Windows 10 using any of Chrome, Firefox, or Edge. All three browsers exhibit the same behavior - a blank browser window, no apparent errors in the terminal console, but warnings and errors in the browser console relating to MIME type problems. I'm including screenshots here for reference.

Edit: paying close attention to BLGAmazingJ and the diff in this PR, I was able to find the right file and make this change manually. Once this was done, I no longer have the described problem.

[minrk]

Excellent, thank you!

[minrk]

@meeseeksdev backport to 5.7.x

[monocongo]

I have tried moving my version of notebook back to 5.7.4 but no luck so far. Can someone comment as to how I can build from source into my conda environment, in order to leverage the fix described in the comments above? Or will this fix be included in an upcoming release that I can utilize via conda update notebook?

BTW I have tried the following command, but it failed with a compilation error regarding a missing "bower" (which I was not able to find/install, so I gave up):

$ pip install git+git://github.com/jupyter/notebook@5.7.x

Thanks in advance for any assistance with this!

[minrk]

Working on publishing 5.7.7 now.

nodejs and npm are needed to build notebook from source.

[jamesmyatt]

Is there a way of fixing the root cause, i.e. that the registry has the wrong mime type?

[minrk]

I'm not a Windows expert, but from this, it appears to be in HKEY_CLASSES_ROOT\MIME\Database\Content Type. I think the root cause is installation of certain software may modify this database, perhaps as a way of associating itself as an opener for file extensions.

[minrk]

5.7.7 is on pypi

[jamesmyatt]

Thanks, @minrk . I found it in HKCR\.js\Content Type (for Windows 10) and changing that also fixed this problem.

[EAly]

Can anyone help how to apply this solution, i.e how to "add in a mimetypes override for .js files"?!