Somewhere in your action list in your GUI based test you are missing a bracket.
Since a GUI to TCL generated test is a literal conversion of the GUI based test and as such checks all the syntax even if something was commented out in the GUI version. So if you had missed a bracket in your action list it will be converted without the bracket and cause an error in the TCL test.
For example if you had the following in your action list ( note the missing bracket at the end of action)
# return value : {"result":true,"returnValue":
When it is converted we add a " {" at the beginning and another "}" at the end so we get the following which will throw an error.
{ # return value :{"result":true,"returnValue":}\
If we correct the action list to:
# return value : {"result":true,"returnValue":}
The TCL test gets generated with the correct syntax:
{ # return value :{"result":true,"returnValue":}}\