Same issue here. I'm using the online version to get around the issue now. Hoping we see a fix from either Apple or Microsoft soon. I cannot even get a crash report to help determine the cause of the issue.

I created a new profile and it worked for about 30 minutes. It crashes and creates a crash report to send to Microsoft. I've tried traditional Outlook and "New Outlook" both crash. Microsoft Error Reporting log version: 2.0 Error Signature: Exception: EXC_BAD_ACCESS ExceptionEnumString: 1 Exception Code: KERN_PROTECTION_FAILURE (0x0000700009878ff8) Date/Time: 2021-08-24 17:43:35 +0000 Application Name: Microsoft Outlook Application Bundle ID: com.microsoft.Outlook Application Signature: OPIM Application Bitness: x64 Application Version: 16.53.0.21082201 Crashed Module Name: libsystem_malloc.dylib Crashed Module Version: unknown version Crashed Module Offset: 0x0000000000000b76 Blame Module Name: unknown Blame Module Version: 16.53.0.210822 UnsymbolicatedChecksum: A0134613ED94F505E090B52058EA111B Blame Module Offset: unknown StackHash: 460ca6a19a164a55-dm_1_bk_oom Application LCID: 1033 Extra app info: Reg=en Loc=0x0409 Build Type: Release Crashed thread Stack Pointer: 0x_0000700009879000 Crashed thread: 43

I opened up Outlook this morning and tried it again. I'm running the latest version of MacOS and Outlook V 16.53 (21082406) and everything is working again. I did not apply any updates since last week so I'm not sure why it started working.