Search the word "check_onjoin" in all of your tcl files. The script file containing that word would obviously be the one causing the error.
By the looks of the name, (check_onjoin) it may be triggered when a person or the bot itself joins a channel which the script is working on. Binded on join I think.
You can also type this in partyline for more information:
(Given that you have the dcc:tcl unbind 'commented' in the .conf file)