Data upload incomplete / corrupt

The data upload to the Zwift server fails once a while, i would say in 1 out of 15. The record can then be opened in companion app, but detail data is missing. I am pretty sure it’s a problem with the speed of data connection and/or heavy load on the server.
But i am quite sure this problem can be solved on server side.
Anyone else with the same problem?

Your symptoms are of a network issue between your Zwift device and the Zwift servers (commonly wifi related but can be anywhere). You should grab the log from one of those rides and chuck it on Zwiftalizer.com to see if it is seeing network errors. If it is, you can diagnose from there (ie, have a read of log file). Some network errors may indicate a problem with Zwift but more commonly point to a network issue local to you - you should approach support.zwift.com if its them.

Thanks for your help. Indeed there were a lot of network errors (> 50) about ten minutes after start, each of them related to a “TCP Connection attempt”, (which should mean the connection was lost before). Indeed probable there has been an error in the local network, but how can i know? I’ll look at support-zwift-com soon, right now the connection is fine…

If you are windows: a simple thing to do is the next time you do a similar event (# of riders) is to run a ping from your Zwift device continuously to a well known external host, like Google DNS. In Windows, you may need to increase the cache size of the window (if needed) as well to capture all results for the duration of your activity.

The next time you have those symptoms, you can compare your ping with the timing of network errors (the log file has the exact times). If ping dropped as same time, then problem is likely in the network somewhere. If ping stays up but you have network errors in log, then Zwift hosts are likely refusing your network connection for some reason and would require Zwift to diagnose.

BTW, you can run multiple pings to other devices in the house, at your ISP etc to start isolating where the network error is as well - pings have very low overhead. If you suspect your environment is dodgy, ping to your gateway, ping to another PC etc can help pinpoint.

A TCP issue 10 minutes into the ride should have no affect on Zwift FIT file upload at the end of the ride (unless 10 min was all you rode…). Had your connection completely severed, you would have found yourself alone in whatever world you were riding in.

Zwift seems extremely sensitive to networking issues while uploading the FIT file to Zwift servers. Indeed, this is a single point of failure for your ride upload. In that sense, do try to improve your network connection.

At the same time, as long as your connection is reasonable, file upload under such conditions was solved more than 20 years ago.

Thanks a lot for your hints… I reconfigured the hardware of my network, adding one more network repeater near the “Zwift-device”. It is too early to say the problem is solved, but the last upload events seemed to be a lot faster than before and didn’t fail. Well, i would say the problem is solved, but to be definite with this, i will have to try some uploads (let’s say: days) more.
Thanks Dean, B_CN.

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