What does "read only" mean as an error message?

we are getting a read only error message for variables.
please help me. what does this mean? and how do we debug it?
thanks!

It means you are using a variable name that code.org is also using for their stuff too. I think this is a mistake made by a developer and have already opened a bug months ago.

There is nothing to debug you just change the variable name you are using. For example name and location cannot be used by students. Speed is a function used by the turtle graphics package, so that can’t be used by students.

@sandiferc What variable names are you getting the read-only error for? Please share a link with the code. Also, take look at the App Lab documentation. It has detailed instructions on how to use the interface. Please let us know if you have more questions.