Keenetic Air and version 2.06 are completely discontinued. Please, install either 2.16 from the "legacy" channel, or 3.07 from the Dev channel, there is at least some hope for unofficial support.
https://help.keenetic.com/hc/en-us/articles/360000440120-Saving-the-self-test-file
Please attach your diagnostics to this topic, and then Hide as it may contain sensitive information. Also, feel free to contact the official support in your country: https://help.keenetic.com/hc/tr