@atripp yes that appears to be the cause of the error. It doesn't seem to prevent us from downloading packages so perhaps it is just seaching that won't be available.

DEBUG: 2021-08-27 04:36:35Z - Downloading repository index from https://maven.google.com/.index/nexus-maven-repository-index.gz
DEBUG: 2021-08-27 04:36:35Z - Local index path is /var/proget/packages/.maven2/C8
ERROR: 2021-08-27 04:36:37Z - Unable to download repository index: The remote server returned an error: (404) Not Found.

I've reproduced this error now in two separate installations of Proget. Both are running ProGet Version 5.3.36 (Build 4), one is in a docker container hosted on Centos linux, and the other was installed on a Windows server using Inedo Hub. We've configured multiple types of feeds (nuget, npm, maven) and only the maven feed is showing this problem.

Here are the steps I took to reproduce the error in the second installation.

1. Installed Proget on Windows using Inedo Hub
2. Configured a maven feed, and added a single connector to https://repo1.maven.org/maven2
3. Executed a maven build using the Proget feed for the repository
4. For every artifact that Proget mirrors from the Maven repo, all of the POM files are zero bytes in length. All of the artifact metadata is correct (description, version numbers etc) however if you directly download the POM file from the feed, it is always zero bytes. e.g., http://localhost:8624/maven2/test-maven/org/apache/maven/plugins/maven-resources-plugin/2.6/maven-resources-plugin-2.6.pom

I've done the following analysis.

• The files on disk are zero bytes in size in Proget's package store at C:\ProgramData\ProGet\Packages.maven2
• Using Fiddler as a proxy, I can see that ProGet is successfully connecting to the maven repo and downloading the files and that there is no connection problems and the entire contents of the files are being transferred.

So the issue appears to be happening when saving the files into the ProgramData storage. Since I've reproduced this on two completely different installations that are even running on different networks, and since Fiddler shows me that the HTTP transfers are successful and contain valid data, the problem seems to be with ProGet.

The only error messages I can see in the Diagnostic Center look to me as if they are side effects of ProGet trying to process package info from zero byte files so are not the cause of the problem.

@atripp The error appears to have stopped happening for the maven.org connector, however I'm still getting it for the connector to the google maven repo. Their feed url is https://dl.google.com/dl/android/maven2/

It appears to be able to connect to that repo and download packages even though the health check is failing, so its unclear whether the health check failure is actually causing any problems.

We're using ProGet Version 5.3.36 (Build 4)

I've got a different error though now that I'll open in a new thread because it seems unrelated to this one.

My connector to maven.org simply won't work. I can see the following error in the log. Connector maven.org health check reported error: Object reference not set to an instance of an object.

The connector's configuration is as simple as it gets. Not sure what else to try? This is the final remaining thing I need to get working in the trial version before we purchase ProGet next week.