First, install Construct 2 r206, make a blank project (just for example)
Add a Text plugin
Type some text in it. For example: ABCXYZ... blah blah blah... and save it in somewhere.
Ok. Now uninstall the r206 one and install r210.
Open the project in r210. Edit the text again, for example XYZABC... and save it.
Uninstall r210 and reinstall r206.
Open the project again, and you see this error