When I got Live 10 beta I was stoked!!! It took a while to load, but whatever. Then when Live 10 released officially the load times were still slow. Over time I came to find out it was not everyone, but just me. Going down the rabbit hole I found a solution.
This video walks you through how to fix the Option.txt issue as well as the slow startup issue I was having.
Ableton Live Option.tx File
To find the Option.txt file, try these to places. The folders are hidden by default. Here’s how to access hidden folders on Windows and Mac OSX.
Finding the MIDI Remote Scripts folder:
The Remote Script folder is located inside the Ableton Live application bundle. To access it, locate the Live application in Finder, right click on it and select “Show Package Content” in the appearing context menu. Then navigate to: /Contents/App-Resources/MIDI Remote Scripts/
Look for the folder where you installed Ableton Live. Something like this:
C:AbletonLive x.xResourcesMIDI Remote Scripts