OBFL is on-board failure logging, this is a subsystem that contiuously logs all environmental data to the bootflash: of the router boards, so our development can identify trends & root causes in case of multiple long-term hardware failures, for example. Here a file got corrupted during the multiple read/write, it can happen.
Try the following, where x is the linecard reporting the error:
(admin)#clear logging onboard corrupted-files location 0/x/CPU0
Clear logging onboard corrupted-files [confirm] [y/n] :y
If that doesn't stop the mesage you can manually delete the files starting with 'temp' on the bootflash of the affected board.
This has no impact on router operations.