Project ID &1 is invalid

What causes this issue?

The naming conventions of delivery requests must contain a valid project
ID or a valid namespace. Project ID &V1& is not valid.

System Response

You can enter a new project ID, or correct the naming convention.

How to fix this error?

You need to enter a project ID (using the appropriate naming convention,
where x stands for a given character and n stands for a given number):
Project ID,,Project Type
Gxx<,,Enterprise Extension
Ixx<,,Add-On Development
Jnx<,,Partner Development
Nxx<,,Application Platform
Pxx<,,Country-Specific Development

Error message extract from SAP system. Copyright SAP SE.