mautic.EMERGENCY: lead not found

Your software
My Mautic version is: 2.15.1
My PHP version is: 7.0.33

This error is howing in the log. I’ve searched around a lot and can’t find any reference to it anywhere.

mautic.EMERGENCY: lead not found

They are 5-10 seconds apart. Strangely the time stamps in the log are out of order

Have you tried upgrading to the latest version? You’re a bit out of date if you’re running 2.15.1 - recommend upgrading at command line after taking a backup of files & database. Steps to follow are here: https://www.mautic.org/docs/en/tips/update-failed.html

Yes I suppose we are going to have to bite the bullet and upgrade. Have had serious issues with bugs introduced during upgrades in the past. Broke our campaigns and then when we put in suggested workarounds it made a real mess. So a scary proposition.

We’ll do the upgrade and watch carefully

You could do a backup and upgrade offline in a development area to test for any problems - that way you can also test going forward. Let me know how you get on!