Subscription for &1 deleted in source system &2. See long text.

What causes this issue?

You are trying to start a delta request (no delta initialization). The
subscription for &V1& was deleted in the source system &V2&. There is an
inconsistency between the source and the target system. If the current
request would be processed by the source system, older records would be
extracted again.

System Response

The request processing is canceled.

How to fix this error?

You have two options:
Re-initialize the delta. In the administration view of the target of
&V1&, delete all delta requests that originate from this DTP. The system
will then run a new delta initialization which will create the
subscription again in the source system.
Run a request manually with the processing mode 'No Data Transfer; Delta
Status in Source: Fetched'. This will create the subscription again in
the source system but could cause the loss of any data records
created/modified in the meantime (between the end of the processing of
the last successful DTP request and the manually created request run).

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.