3037484 - In Plan Customer Projects app, error "Sorry, the plan data couldn't be saved due to errors." when setting Stage "In Execution"

In app Plan Customer Projects, you try to set Stage "In Execution" for a project and get error "Sorry, the plan data couldn't be saved due to errors."

SAP S/4HANA Cloud

1. Open app Plan Customer Projects
2. Open a project
3. Set Stage to "In Execution"
4. Click Save
5. Receive error "Sorry, the plan data couldn't be saved due to errors."

One possible cause is missing currency exchange rates.

Maintain the currency exchange rates in app  "Currency Exchange Rates" for currencies and dates relevant to the project for rate type P (Cost Planning)

FINS_ACDOC_PLANNING015, FINS_ACDOC_PLANNING 015, LT_ACDOCP_DATA_EXTENDED, SG105, SG 105,  2979593 , KBA , CA-CPD-SS , S/4HANA Professional Services Cloud - CPM , Problem