Why am I getting "Error -1,752" when trying to save in Script Editor?
The problem is that the file is a plain text file. When I originally created the file in 2007, Script Editor could apparently save uncompiled .scpt files. Now, however, as described  in Can&#39;t save AppleScript file when created by touch, .scpt files must be compiled. Uncompiled files can be saved with the .applescript extension.

I know this is nearly a duplicate of the question linked above, but I added it because as of OS X 10.11 El Capitan Script Editor gives an error number for this problem. I couldn't find any other references to this error number so I thought it was worthwhile to get the error number in a question title.