Hagar Delest wrote:The cache may have not been written fast enough before the battery died...
It is not generally realised that there are two caches - one in software, where the data to be written to disk is queued and flushed at regular intervals, and then one internal to the disk, where the data is held in short term memory while the disk heads move to the correct position. Sudden power failure, however caused, can erase the data in one or both of these.
There is an outside chance that an undelete utility might recover an earlier version; the less use your comuter has until such a utility is tried, the better, so search and download one on another computer.
Apache OpenOffice 4.1.8 on Xubuntu 20.04.1 (mostly 64 bit version) and very infrequently on Win2K/XP