#Index: Failed to load index files on initial index synchronization

[gtandersen]

Describe the bug
Sometimes the index file(s) download fails with this type of error:
Failed to load https://runbox.com/mail/download_xapian_index?fileno=3. A ServiceWorker intercepted the request and encountered an unexpected error.

Object { headers: {?}, status: 200, statusText: "OK", url: "https://runbox.com/mail/download_xapian_index?fileno=3", ok: false, name: "HttpErrorResponse", message: "Http failure during parsing for https://runbox.com/mail/download_xapian_index?fileno=3", error: abort }

The error is not consistent for the same account without reindexing, so it appears to be a problem with the transfer and not the files themselves.

To Reproduce
Steps to reproduce the behavior:

1. Go to https://runbox.com/app
2. Click "Synchronize index"
3. Observe above error

Expected behavior
The index files should download without any error.

Desktop (please complete the following information):

• OS: macOS
• Browser: Firefox 96.0.3

[gtandersen]

Not seen this issue recently.

[gtandersen]

This is occurring again in Firefox on macOS with this error:

Http failure response for https://runbox.com/mail/download_xapian_index?fileno=4: 0 Unknown Error

The download succeeded after multiple attempts.

[gtandersen]

This could be alleviated if the index download would automatically resume when it fails.

[gtandersen]

See also #1046.