An application crash can be due to any number of reasons. The following are a few common ones:

The application is not compatible with the hardware or operating system that it is running on.

The application was upgraded to a newer version of 4D, but its plugins/components/resources were not updated for the new version.

Some part of the application’s code is faulty.

The structure file or data file is corrupted.

Power failure.

Faulty hardware components.

When initially encountering a crash, check for hardware and OS compatibility. Also, verify that all plugins, components, and resources that the application relies on is up-to-date. Then, try restoring backups of the application and test for the crash. If the restored application does not crash, some code or data introduced at a later point to the application could be the cause. Only attempt to repair the data file after restoration of backup proves ineffective.