Arcgis runtime sdk .net - error 'Failed to create replica'

[PalakPandey]

I am using Arcgis runtime sdk .net 100.9. While generating offline map I am getting and error 'Failed to create replica' for all the layers in layerErrors. However, the error is not consistent sometimes the download happens without any error. The chances 

The sync is enabled for feature layers consumed in Webmap

[JoeHershman]

Are you using in-house portal?  If so check the ArcGIS Server log it may give some additional information

[PalakPandey]

Hi Joe, Yes I went through the log at server end which shows 'ArcGIS Data Store has detected a replication failure'  and alss 'Underlying DBMS [disk image is malformed]'. But I am using the same db for offline map generation in geocortex and other places. Everything works fine.