Hey Charjabugz,
There are versions of Wurst that make it more obvious what this error message means, yes, but actually solving the problem is always possible regardless of your Wurst version.
The "Chat disabled due to missing profile public key" message means that the server you are playing on is trying to force you to send chat messages that can be reported to Mojang (also known as "signed messages"), which is something Wurst doesn't allow by default to keep your account safe.
If you are comfortable with the risks involved, you can re-enable reportable chat messages by turning off the NoChatReports feature in Wurst. In modern versions, you'll find this under the "Chat" category in ClickGUI. Just toggle it off.
If you're using an older version of Wurst before v7.35.2, or if you prefer to use the Navigator GUI, you can find the same feature by opening Navigator and searching for "NoChatReports".
However, do note that by disabling NoChatReports, you run the risk of being chat-reported and potentially banned by Mojang. See this FAQ for more details on the risks of chat reporting.
Hope this helps! Let me know if anything is unclear.
