Must use an old beta version of iperf3 on the PC side – WiFiPerf Review

This version of WifiPerf is built against an old beta version of the iperf3 library which isn't compatible with *any* of the stable releases ESNet has made in the past year. If you ask the app's creator to upgrade to the current version of the library so you don't have to install beta software on your servers just to accommodate their outdated testing tool, they give you a sob story about how difficult that would be. Here's a clue, guys: you're riding on the coattails of a popular test tool, iperf3. If you want to sell your app as "compatible" with it, you must keep up.
Review by Fred Yazzie on WiFiPerf.