Is your windows username using any non-latin characters? Only a guess, not sure if this matters but it does for the Minion addon manager e.g.
Ingame use this chat text editfield command (copy it to the chat editbox and press the RETURN key) to switch to the English client properly:
Code:
/script SetCVar("language.2", "en")
A reloadui will happen afterwards!
If this does not fix it, try this:
Logout AND close ESO before updating the addon or the client!
Delete the complete folder live/AddOns/TamrielTradeCenter.
Delete the file live/SavedVariables/TamrielTradeCenter.lua
Download TTC manually from the website (
https://us.tamrieltradecentre.com/download) and install manually into your adons directory like described here (ESOUI, general addon install hints)
https://www.esoui.com/forums/faq.php..._howto_install and here
https://us.tamrieltradecentre.com/help/AddonAndClient (TTC install instructions).
Add the folder live/AddOns/TamrielTradeCenter to your antivirus and firewall software whitelists/exclusion lists/allowed lists so that the client.exe is able to communicate and run.
Run the client.exe file and update the prices table files.
Then afterwards start ESO launcher and client, login, proof the versio shown ingame is the same as is shown at
www.esoui.com for TTC, and check if it works now.
If the version differs you might have installedit into the wrong folder or the game tries to read addon data from another folder.
Take a screenshot and look at the right upper edge of your ESO client, it will tell you the folder where the screenshot is saved. If this is not the same (like /live/Screenshots) where your addons are installed, try to move the addons to this's folder live/AddOns.
BUT: Always LOGOUT before changing addon filesor folders!