Start-up issues for Pages, Numbers, and Keynote

If these Apple applications are installed on the internal startup drive in the Applications folder, then taking Pages as an example, press and hold the shift key while launching Pages. That will cause it to ignore its last saved executiion state, and may break you out of this crashing cycle. You would only need that shift key approach after a hang or crash event.

If you have installed any anti-virus, or so-called Mac Cleaner application, I would thoroughly remove them per the vendor's instructions. Sometimes, these classes of applications flag a legitimate file within an application bundle, and once removed, destroys the application's normal ability to launch and run properly.

I have a 2020 Core i7 iMac with v14.4 of Pages, Numbers, and Keynote installed on the internal SSD. The iMac is running Sequoia v15.4.1 and I have no issues with these applications.

Boot into Safe Boot mode with your iMac by pressing and holding the shift key while rebooting. This will rebuild the font database, clear system caches, and check your drive. It also prevents third-party applications that might otherwise load drivers from doing so.

Once in Safe boot mode, press and hold the shift key during the launch of Pages. Does it crash, or does it present a Template or File chooser?

Reboot normally, and launch Pages again. Does it work now?

By Pages working in Safe Boot Mode, and not in normal boot, that suggests to me that you have installed something that is actively interfering with Pages when in normal boot mode. What did you install recently, after the Sequoia upgrade and before Pages issues began?

Consider downloading the free EtrecheckPro, and give it full disk access in System Settings > Privacy & Security panel. Run Etrecheck, copy its report to the clipboard, and then use the Additional Text icon in this editor to paste and post that Etrecheck result. It is user privacy safe, and its report allows me to see what software and drivers you have installed.

I have the same problem with my Macbook Air M1, just updated to Sequoia: all the presented solutions do not work. Please help.