i have applied below CSP policy and changed my GWT version to 2.8.2 after that i am getting below error for PRC call ( to read Database and populate the data in UI and save data to DB) and button clic

i have applied below CSP policy and changed my GWT version to 2.8.2 after that i am getting below error for PRC call ( to read Database and populate the data in UI and save data to DB) and button click ( front validations , read data from DB ..etc). Error Details : java.lang.Exception:

GWT RPC call not working after apply CSP and change GWT version 2.8.2

i have applied below CSP policy and changed my GWT version to 2.8.2 after that i am getting below error for PRC call ( to read Database and populate the data in UI and save data to DB) and button click ( front validations , read data from DB ..etc). Error Details : java.lang.Exception: