You created a PDI Solution under Customer ID 0001234256 (0001234256 represents the ID of the Customer) in your Partner Development Tenant.
When you try to upload this PDI Solution in the Target System (Customer's Tenant) you get the following error:
"Upload not allowed. Solution is developed for customer 0007891011" (0007891011 represents the ID of the Customer)
You get this error message because you have developed the PDI Solution under a different target Customer ID.
This is the expected behavior of the system.
Partner Solutions can only be uploaded in the Target Tenant set when you started developing the solution.
If a PDI Solution is developed for a particular Customer ID it is not possible to switch it to a new Customer ID.
The only way to change it would be to re-develop the solution for a new Customer ID.
KBA , SRD-CC , Cross Components , How To