App Descriptor for id &1&2 was not found by App Index search

How to fix this error?

Depending on the root cause, proceed as follows:
No SAPUI5 Fiori App with this ID exists.
In the launchpad designer, check the entry of the ID field of the
tile/target mapping configuration.
A SAPUI5 Fiori App with this ID exists in the SAPUI5 ABAP repository,
but the app index is not set up correctly
Ensure the app index is set up correctly. See https://sapui5.hana.ondema
nd.com/#/topic/c5e7098474274d3eb7379047ab792f1f
A SAPUI5 Fiori App exists outside the SAPUI5 ABAP repository; an app
descriptor exists but for this case is not returned by the app index
search
Known case: SAPUI5 Fiori Apps provided by /ui2/ushell library - check TM
in Launchpad Designer, see value for "URL"

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.