The software solutions are fixed when there are no bugs on the laptop or computer. The scenario is the same with your wavlink ac750 setup, you have to keep it up to the mark. Although the extender shows setup errors even if you keep the extender updated. The lack of Setup knowledge might be an issue. You can follow the steps. Although the process is not at all a time taking. Open up the web browser, and type the web address in the web browser for example wifi.wavlink.com in the space of your URL. Therefore, find the update button. This is the best way as this process helps you login into the portal directly. If in any case, your documentation crashes, hopefully, your firmware will fix it. Give it a shot. And you will be done with the process in this easy way.