For a couple of years I have been using a Sony camera with a time-lapse app from playmemories. Yesterday it stopped working. A warning mentioned I had to move content from the app.
I tried to empty my sd-card (in camera) with no result: the same warning appeared.
Back home I had to format the card in my computer after which everything was working again.
Seems like the app is counting the total number of exposures (in different sessions) on the sd-card and stops after 999 exposures.