Text autofit improvements not compatible with latest Storyline 3

It's my understanding that 360 projects default to having the autofit option off. But when it's enabled, storyline prompts to save a backup copy as it's a global change. I believe that even if you had a blank project and deleted all the slides it's still something that is enabled for that file. I think the autofit is a good feature and has its place, but isn't backwards compatible - it seems. Sorry you're having trouble. If you are in a mixed dev environment, here is a list of other difference that could crop up for you. https://articulate.com/360/storyline#compare 

All that being said. I just tried something that worked for me to restore a file to a stage before updating the autofit. This is a very hacky approach and you absolutely MUST MUST MUST do this on a backup of your file. 

I took my 360 storyline file with autofit enabled. 

• I duplicated the file.
• If windows doesn't show your file extensions then enable them under the folder view options so you can see the ".story" extension.
• Rename the duplicate file by removing ".story" and adding ".zip"
• Unzip the folder
• You'll see a number of folders. We are going to change 3 files in here. Use notepad, not MS Word.
• Edit theme.xml in the \story\theme folder. Change "true" to "false" where is says "usenewautofitdefaults"
• Edit the featureManifest.xml file in the docProps folder. Remove the portion that starts with "<TextScrolling2" and ends with the next "/>"
• Edit the story.xml file in the story folder. Near the top change two things: change "true" to "false" next to both "usenewautofitdefaults" and "autfitupgraded".
• Select all the folders that (not the parent folder) of what you had unzipped and rezip it all.
• Rename the zip file to remove the ".zip" portion and add ".story"

When I did this and opened the story file in 360 the option for autofit had been restored to its previous state. I was unable to test the output file in storyline 3. 

I've attached below the storyline 360 file that I had upgraded to autofit then manually downgraded using the above. Feel free to test opening it in storyline 3 to save you the time if the above steps won't end up working.

Please Please, for all that is holy, do this on a backup of your project. Somewhere out there an articulate dev is shaking their head at me for this craziness.