Windows updates will always require a system restart after installing. This can pose a dangerous situation for 4D databases running as services. When a system restart takes place, the database may not fully flush its cache—especially in cases where the cache itself is very large.

Upon opening the application after the system restart, a "1173: Cache flushing did not complete" error may be raised, and the database structure cannot be opened. At this point, the database administrator may come across some data loss and must restore the database from a backup.

For preventative measures, ensure that the cache is set to flush at frequent intervals. This can be done by changing the value in the in the "Flush Cache every" setting in the database settings window under Database > Memory (see below):

The default value of 20 seconds should suffice. Anything upwards of a minute may too long of an interval.


It is also recommended to handle Windows updates manually, rather than using the automatic updates mechanism. Shut down the database before installing a Windows update to prevent the earlier described situation from happening.