That's because there is a long-standing bug in the software. When you set up automatic saving (select automatically save document changes to temporary file every XX minutes" it changes your user preferences in the AppData>Roaming...UserPrefs file. Except, instead of setting the parameter as "1", it sets it as "true". I'm assuming this was just a typo in the code that hasn't been corrected for years. If you manually go into that file and change "true" to "1", then it works perfectly.
That's because there is a long-standing bug in the software. When you set up automatic saving (select automatically save document changes to temporary file every XX minutes" it changes your user preferences in the AppData>Roaming...UserPrefs file. Except, instead of setting the parameter as "1", it sets it as "true". I'm assuming this was just a typo in the code that hasn't been corrected for years. If you manually go into that file and change "true" to "1", then it works perfectly.