On a Mac, Excel sometimes will quit unexpectedly with the following in the crash report: -
Termination reason : Namespace DYLD, Code 1 Library missing
Library not loaded :'@rpath/ADAL4.framework/Versions/A/ADAL4
Exception type : EXC_CRASH (SIGABRT)
To clear this, you will need to do the following: -
Re-install Excel as follows:
1. In the Applications folder drag Microsoft Excel.app to the Mac OS Trash
2. Restart your Mac
3. Empty the Mac OS Trash
4. Use this installer to reinstall Excel: Excel
Once installed, start Excel and go to Help > Check for Updates. This will show the 365 update manager and show that Excel has an update waiting to be applied. Allow it to download and install and check Excel opens and allows the user into their documents.