In certain cases on a Domino 8.5.2 FP1 server, the contents of the Domino data directory can be deleted during shutdown on UNIX and Linux platforms. This does not happen frequently or on all Domino servers. However, if this does happen, a backup restore of the data will be necessary....This issue has been reported to Quality Engineering as SPR# DWON8FVMYS and will be fixed in Notes/Domino 8.5.2 FP3 and 8.5.3. To obtain a hotfix for this issue, open a service request with IBM Support.