osexp cannot be opened when logger includes invalid variable name

[krajcsi]

If you add a variable to log that has an invalid variable name (e.g., including . = ?; because mistyping it or using some special characters for placeholders), the script will run (at least with the osweb backend), and the script can be saved, but when the osexp is opened, OS cannot read it, giving the following error message:

Failed to open
Failed to open the file for the following reason:

Error: InvalidOpenSesameScript
{var} is not a valid variable name

This error occurred in the unknown phase of item unknown.

[smathot]

Thanks for catching this! This is quite a severe issue.