Numerous XPC errors

Dear all,

I noticed that my system.log contains 9000+ lines of this type:

Apr  5 00:00:05 PNeruda com.apple.xpc.launchd[1] (com.apple.mdworker.mail.08000000-0000-0000-0000-000000000000[17816]): Service exited with abnormal code: 1
Apr  5 00:00:14 PNeruda com.apple.xpc.launchd[1] (com.apple.mdworker.shared.01000000-0000-0000-0000-000000000000): Service only ran for 2 seconds. Pushing respawn out by 8 seconds.
Apr  5 00:00:14 PNeruda com.apple.xpc.launchd[1] (com.apple.mdworker.shared.03000000-0000-0000-0000-000000000000): Service only ran for 2 seconds. Pushing respawn out by 8 seconds.

What should I do?

Many thanks for your advice.