How to turn off auto text box

Hi Heinz! I apologize for the issues you are experiencing trying to upload your course in Storyline 3. Can I ask why you are trying to open a course created in Storyline 360 in Storyline 3? 

The update Ren is referring to came out on July 27, 2021 (Build 3.54.25674.0). Since this update is no longer available in the desktop app (only the previous 6 updates would be), you can reach out to support@articulate.com if you need an update prior to this one. 

Text autofit improvements are exclusive to Storyline 360 and part of our ongoing commitment to making courses fully accessible to all learners.

You can also take a look at this article on compatibility between Storyline 360 and Storyline 3 project files.

Please let me know if you have any additional questions.