Remote User Error 400

[swalton]

I have a remote user connected to our Vault Pro 2018 server via VPN.  The user is usually able to download vaulted files one-at-a-time, but gets a "The remoter server returned an error: (400) Bad Request" error on some files when he does a "Get" on a large set of files.  Sometimes he gets the Bad Request error on individual files too.

I had to add a FLEXLM timeout system variable to the remote workstation to pull inventor/vault licenses.

I have increased the timeout on the Vault Server, but that has not made a difference.  Ping is around 250 ms between the remote workstation and the Vault Server.

We do not have issues for local users connecting to the Vault Server via our internal network.

Any ideas on what to adjust/change on the Server or the Client workstation?

[johannes.bauer]

Hi Swalton,

Have you reviewed this KB Article to see if it helps?

Does the issue also occur if the user is connected without VPN?

[swalton]

@johannes.bauer,

Its taken a bit to troubleshoot, but here are the results.

Disabling the AV product on the user's workstation seems to fix the issue.  We are trying to figure out how to keep the AV running, but allow the Vault communication.  The workstation has McAfee Total Protection version 16 installed.  The user is re-installing Vault while the AV is disabled.

We can't connect this specific workstation without a VPN due to geography/network topology.

[michael.battcock]

Hi Swalton,

I'd start with troubleshooting the AV and ports that the firewall is blocking. You're on the right path here if disabling the AV fixed the issues. Try using this guide to troubleshoot. At the bottom of that guide, there are some very helpful "See Also" guides that can help with this. I imagine adding exclusions and white listing the Vault processes with help with this issue.

[swalton]

@michael.battcock

Thanks for the guide.  I'll take a look and see what we can change.

I had another screenshare with the user.  I miss-understood him when he said it works with the AV shut down.  He meant that he could log into Vault, not that he could actually download files.  So we have not found a source of the error.

He as since tried uninstalling the AV software and running Vault.  In that case, he still gets the 400 error.

His ping to our server is on the order of 250 ms, not sure if that makes a difference with Vault. 

[michael.battcock]

Would be interested to see what would happen when running a traffic capturer like Fiddler simultaneously while reproducing the issue. This might help us dive a little deeper into what's the root cause of this issue.

[reidmatthew]

@swalton Thanks for your patience and looking into this behavior with your customers. @johannes.bauer and @michael.battcock have given some great advice and ideas so far. I would like to add my two cents to the conversation also.

I have seen error 400 related to Vault traffic before be caused by the HTTP packets themselves being out of order or missing information in the headers. This can be caused by lots of things including antivirus, proxies, and more. Most recently I saw it with a customer who had 2 sites, one in the US and one in Asia. There was a lot of latency in the network connection between the sites and also some rerouting of traffic through proxies it seemed. This lead to the packets being out of order and not able to be deserialized correctly and the HTTP error 400.

I would be curious, as @michael.battcock mentioned, to see the results of a Fiddler traffic capture, as well as any errors in the Vault logs related to the HTTP error 400 or something like "UnspecifiedSystemError [0]" or "deserializing" problems. You can also use something like Wireshark to monitor the HTTP packets themselves to see if they are out of order. Fiddler and Wireshark can be a bit tricky to use  or know what to look for. Their logs have sensitive data such as IP addresses, machine names, etc, also. So you may not be able to share them here on the forum. Share as much as you feel comfortable. And let me know if you need help configuring the tools or deciphering their logs. 

Let me know what questions you have about any of this.

[swalton]

Thanks for the troubleshooting idea.  I'll have the remote user run fiddler tonight and see if we get anything useful.

[reidmatthew]

Hi @swalton I am just following up to see if you have made progress on resolving this issue or answering your original question. Let me know if you need anything else.  As always please hit the Accept as Solution button on the post(s) which provided a solution for your issue or question.

[swalton]

@reidmatthew

My user generated a .har file from Fiddler.  Would you be able to take a look if I sent it to you?  Is there a better file to send?

[reidmatthew]

@swalton a har file may work. Fiddler usually produces saz files. I will send you a private message about how to proceed going forward.

[swalton]

@reidmatthew

I have some files I'd like to add to the case, but I can't seem to get access to it through my Autodesk Account. 

Is there something I am missing?

[reidmatthew]

@swalton and I have been working on this and suspect the issue lies with the VPN client connection with the remote user. @swalton is going to work on this with his IT team for a resolution. Please let us know what you find out as others may run into similar issues in the future.