BWA index for InfoCube '&1' is "inactive". No queries currently possible.

What causes this issue?

The setting in transaction RSDDB is "Query stops if BWA index not
found", and BWA index '&V1&' is inactive.
Reason for being inactive: A BWA index can be set to inactive manually
in transaction RSDDB. A BWA index can also be set to inactive
temporarily if the data in the indexes is currently being updated, when
a request is deleted for example. The index is then soon set to active
again.

System Response

The query stops.

How to fix this error?

Check the settings in transaction RSDDB under the "BWA Index Settings"
tab page.

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.