3785401 - Error: "Your chart is missing one or more entities" appears when trying to create a new story based on BW live model in SAP Analytics Cloud

• Below error appears while trying to add a specific dimension while creating a new widget in SAC based on a BW live model:
  "Your chart is missing one or more entities. To prevent loss of entity information in data queries, before performing any further actions on the chart, please remove the missing entities from the feeds or add those entities back into the model."
• Once this error appears, the Builder Panel UI no longer allows dimensions to be selected, the section is just blank and a pop up to renter credentials for the BW live connection (connection to the backend is lost)
• The issue is not occurring in the Data Analyzer
• In BW side, when using the transaction RSRT, it is possible to use the affected dimension, in the query, while logging with the same BW user used in SAC.
• In ".har" traces, the below error appears:
  "403 Forbidden" in the GetResponse() calls.
  
  

• SAP Analytics Cloud
• SAP BW live model

1. Login to the SAC tenant.
2. Create a new story.
3. Add the BW live model as a data source.
4. Add a new widget (chart / Table).
5. Open builder panel of chart and try to add a specific dimension.
   >> Notice the error: "Your chart is missing one or more entities. To prevent loss of entity information in data queries, before performing any further actions on the chart, please remove the missing entities from the feeds or add those entities back into the model."

A load balancer is blocking communication between SAC and the backend, causing a "403 Forbidden" error.

Update the Web Application Firewall (WAF) regex rules to allow the "/bw/ina" calls.

sac, blocked, loadbalancer, firewall  , KBA , LOD-ANA-DES-CHART , SAP Analytics Cloud core charting , Problem