Can't change install location on Mac OS Catalina
Have been having the same problem with Origin on macOS Catalina. Tried many solutions and finally found a workaround.
Make sure the Origin application is closed.
Open a new Finder window and in the menu bar click Go > Go to Folder... (You can also use the keyboard shortcut SHIFT+CMD+G)
In the dialogue box that pops up copy and paste the following path: ~/Library/Application Support/Origin/ and click Go or press Enter on you keyboard.
Once inside the folder you will see a list of files and sub-folders. One of the files is titled local.xml right-click on it then click Open With... > TextEdit (if TextEdit does not appear in the menu click Other... and then scroll down to find TextEdit and double click it)
The file local.xml should now open in the TextEdit app. The file includes several lines with Settings and Values.
The line we're looking for is this:
<Setting type="10" key="DownloadInPlaceDir" value="/Users/USERNAME/Applications"/>
(your macOS user name will appear instead of USERNAME)
Now in order to change the default Origin game library location all we have to do is change the value in this line to the folder path that we want to use.
For example if you want to change the install location to a folder on an external drive the line should look something like this:
<Setting type="10" key="DownloadInPlaceDir" value="/Volumes/EXTERNAL DRIVE/FOLDER NAME"/>
Of course you must change EXTERNAL DRIVE and FOLDER NAME to the actual drive and folder name on your Mac. On mine for example the external drive is called X5 SSD and I created a folder named Origin on it. So my line looks like this:
<Setting type="10" key="DownloadInPlaceDir" value="/Volumes/X5 SSD/Origin"/>
Make sure you only change the value inside the quotation marks while keeping everything else intact.
When you're done save the changes by pressing CMD + S on you keyboard. Close the TextEdit window.
Now launch the Origin app. If the folder path you entered in the local.xml file is valid Origin should open as usual and you can go to Origin > Preferences in the menu bar. Check under Installs & Saves and you should see the folder path updated under Game Library Location. Any new game you install in Origin will now be installed in the new folder.
If the folder path you entered in the locals.xml file is invalid you will get a pop up window after launching Origin alerting you that games cannot be installed to the folder you chose and that you must change it. You must quit Origin and edit the local.xml file again.
Hope this helps!
