JDBC persist file wont take CRON syntax entries

JDBC into a MYSQL DB on Openhab2 (up to date). Cron syntax entry of:
fifteenminutes : “0 0,15,30,45 * * * ?”

results in an error on persist file save. This just stopped working a few days ago with no changes to my config. Database only has the default everyChange.

Error on save with CRON syntax entry:
Error handling update of file ‘/etc/openhab2/persistence/jdbc.persist’: null

Error on save after removing the CRON syntax entry:
Refreshing model 'jdbc.persist’
Failed to delete cron job for dbId ‘jdbc’

You could write the cron like this:

fifteenminutes : "0 0/15 * * * ?"

But I think, maybe there is another issue in the file, so could you please post the complete jdbc.persist?

No changes were made to the file prior to the change in what was persisted and the errors:
//JDBC Strategies
Strategies {
fifteenminutes : "0 0,15,30,45 * * * ?"
default = everyChange
}

Items {
* : strategy = fifteenminutes, everyChange, restoreOnStartup
}

Checked the installed base of files against their checksums for corrupted files. Only expected changes to the installed karaf .cfg files.

we have some similar (the same?) problem here…
https://community.openhab.org/t/mapdb-persistence-error/23353

did you solve your problem?

No and now the HTTP binding generates:
[ERROR] [org.openhab.io.net.http.HttpUtil ] - Fatal transport error: java.net.SocketTimeoutException: Read timed out

Hi,
Is there any conclusion on this error message: Failed to delete cron job for dbId ‘jdbc’?

I observe that despite this error the persistence works ok (values are stored as expected, in my case every 15 mins) so not sure why it appears?