Why does my device logs stop whenever I receive this error in internal logs?

[aqudoos]

My device logs stopped whenever I received this error in internal logs. How to get rid of this error and why my logs stopped with this error.
ERROR SplunkOptimize - (child_215460__SplunkOptimize) merge failed for path=C:\Indexes\Network_Device\hot\hot_v1_1397 rc=-12 wrc=-12 errno=0 file=dontknow hint=]
Please help.

[p_gurav]

Can you check available disk space?

[aqudoos]

Any one for help ????