[Troubleshooting]
I cannot upgrade firmware to any of the existing new versions: Archer_C50v6_EU_0.9.1_0.2_up_boot[210111-rel37983] or Archer_C50v6_EU_0.9.1_0.2_up_boot[210222-rel54113]. Every time I try I get the following error message: "Error code: 71211 Failed to upload upgrade file! Please confirm the correct file is selected.". Files were downloaded from the official TP-LINK site. Tried on Chrome and Internet Explorer with the same result. What is more, I don't even have a "Firmware upgrade" buton under System tools - I need to manually follow the link /#__softup.htm - which is weird. Please help.
Here is a label from the router: