This can be one of two things,
1. Realtime Endpoints
I am seeing the error "realtime_core" does not exist." how can I fix this? This is usually caused when syncs are set up between two RT (real time) endpoints.
You may have set up a link between two RT (Real time endpoints) this can cause the error RT endpoints need to be specified as bidirectional when setting up the link.
When creating a relation between two realtime endpoints the job type needs to be specified as "Bidirectional Synchronization" Once created the direction of the relation can be specified in "Relation Settings"
How do I fix the sync realtime_core does not exist? Delete the job and create a new connection selecting ‘bi-directional synchronization’.
You can still choose bi-directional synchronization and after creating the link specify the direction of data flow by clicking on the link and in the right sidebar under ‘Direction’ choose either ‘To Slave’ or ‘To Master’.
Source connector "realtime_core" does not exist.
The source process failed.
2. WebHooks Endpoints
This error can also occur when you select RUN from the DSYNC dashboard for webhook API calls, for webhooks to sync you will need to update data within the sending system for a sync to occur.