InfluxDB - structure needs cleaning

I am running my openhab on a raspberry 3 since 1 1/2 years now and have influxdb and grafana installed for logging and visualisation.
Since 3 days I have a problem with my database. No data is saved any more and openhab gives me an error log:

2020-01-2023:49:00.295[ERROR] [org.influxdb.impl.BatchProcessor ] - Batch could not be sent. Data will be lost
java.lang.RuntimeException: {“error”:"[shard 581] lstat /var/lib/influxdb/data/openhab_db/autogen/581/fields.idx: structure needs cleaning"}

at org.influxdb.impl.InfluxDBErrorHandler.handleError ( ~[influxdb-java-2.2.jar:?]
at retrofit.RestAdapter$RestHandler.invoke(RestAdapte ~[retrofit-1.9.0.jar:?]
at org.influxdb.impl.$Proxy162.writePoints(Unknown Source) ~[?:?]
at org.influxdb.impl.InfluxDBImpl.write(InfluxDBImpl. java:151) ~[influxdb-java-2.2.jar:?]
at org.influxdb.impl.BatchProcessor.write(BatchProces [influxdb-java-2.2.jar:?]
at org.influxdb.impl.BatchProcessor$ [influxdb-java-2.2.jar:?]
at java.util.concurrent.Executors$ l( [?:1.8.0_222]
at java.util.concurrent.FutureTask.runAndReset(Future [?:1.8.0_222]
at java.util.concurrent.ScheduledThreadPoolExecutor$S cheduledFutureTask.access$301(ScheduledThreadPoolE [?:1.8.0_222]
at java.util.concurrent.ScheduledThreadPoolExecutor$S .java:294) [?:1.8.0_222]
at java.util.concurrent.ThreadPoolExecutor.runWorker( [?:1.8.0_222]
at java.util.concurrent.ThreadPoolExecutor$ ( [?:1.8.0_222]
at [?:1.8.0_222]

So I understand it sais, the structure of the database needs cleaning.
My retentionpolicy = autogen in influxdb.cfg file.
Any idea what I Can do now?

P.S. I am a beginner so please answer as easy as possible :wink: