When I try to add a new process, I always get an error

Good afternoon. I am trying to add a new process and keep getting this error(ENGINE-09005 Could not parse BPMN process. Errors:). How to fix this, sorry I just started learning camunda

ENGINE-09005 Could not parse BPMN process. Errors: 
  • src-resolve: Cannot resolve the name ‘extension’ to a(n) ‘element declaration’ component. | resource process.bpmn | line 15 | column 70
  • src-resolve: Cannot resolve the name ‘rootElement’ to a(n) ‘element declaration’ component. | resource process.bpmn | line 16 | column 72
  • src-resolve: Cannot resolve the name ‘bpmndi:BPMNDiagram’ to a(n) ‘element declaration’ component. | resource process.bpmn | line 17 | column 79
  • src-resolve: Cannot resolve the name ‘relationship’ to a(n) ‘element declaration’ component. | resource process.bpmn | line 18 | column 73
  • cvc-complex-type.2.4.a: Invalid content was found starting with element ‘bpmn:process’. One of ‘{“http://www.omg.org/spec/BPMN/20100524/MODEL”:import}’ is expected. | resource process.bpmn | line 3 | column 61 [ deploy-error ]