Error in opening file &1 for reading (&2)

What causes this issue?

File &v1& cannot be opened for reading.
&v2&

System Response

The function cannot be executed.

How to fix this error?

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

Procedure for System Administrators

Check whether the R/3 System has access to read for the relevant path.
Check Customizing.

Error message extract from SAP system. Copyright SAP SE.