Does not start Warcraft III

At startup, after entering the login and password from my account, the following says “Error processing request”. And doesn’t enter the game. I can only go out.
There is only a purchased version of Warcraft III: The Frozen Throne

You also need Reign of Chaos.

My game upgraded from Frozen Throne to Reforged.
Should I uninstall it and install reign of chaos?

Install the PTR client and it should ask you for a CD-key. It will have RoC and TFT.

If you’re not sure where to get the PTR client, look here for instructions

And where can I find the key to WC3 ? I once bought warcraft 3 and enter there through … Can I find it a key somewhere in my account?