[NuGet.org Bug]: Large package uploads through the web site fail silently

[agr]

Impact

Other

Describe the bug

When large package is uploaded through the upload page it silently fails. There are errors in JS console in browser dev tools, but the page itself gives no feedback.

Repro Steps

1. Author a package 300 MB in size
2. Go to https://www.nuget.org/packages/manage/upload
3. Try uploading it

Expected Behavior

An error is shown indicating that the package is too large.

Screenshots

Additional Context and logs

No response

[agr]

Response code had changed? It seems there is code to handle the case, but it's checking for a different one:

NuGetGallery/src/NuGetGallery/Scripts/gallery/async-file-upload.js

Lines 195 to 198 in 64e797c

	// IIS returns 404.13 (NotFound) when maxAllowedContentLength limit is exceeded.
	if (fullResponse === "Not Found") {
	displayErrors(["The package file exceeds the size limit. Please try again."]);
	}

[agr]

Also, while messaging is consistent between several locations:

NuGetGallery/src/NuGetGallery/Strings.resx

Line 892 in 64e797c

<value>The package file exceeds the size limit. Please try again.</value>

NuGetGallery/src/NuGetGallery/Scripts/gallery/async-file-upload.js

Line 197 in 64e797c

displayErrors(["The package file exceeds the size limit. Please try again."]);

NuGetGallery/src/NuGetGallery.Services/ServicesStrings.resx

Line 880 in 64e797c

<value>The package file exceeds the size limit. Please try again.</value>

That "Please try again" part is weird. Simply trying again will not help with package size exceeding limits.