Error is shown while cancelling changes

Hi, When trying to cancel the page to cancel the changes, an error is popped up as in the second snapshot.       However, the record is saved in the overview even if the page is closed (the page can be closed only by refreshing the browser) The canceled entry is however, saved as mentioned above (also refer to the yellow highlight in the snapshot below)     The error captured in the console is as below (When clicked on the cancel button)   Kindly assist.
1 answers

An error occurred while executing On click at MyFirstModule.ProjectAttributes_NewEdit.actionButton2:  Error: An error occurred while executing On click at MyFirstModule.ProjectAttributes_NewEdit.actionButton2: 
    at http://localhost:8080/mxclientsystem/mxui/mxui.js?637106200429445780:73:302113
    at ve (http://localhost:8080/mxclientsystem/mxui/mxui.js?637106200429445780:35:8729)
    at r (http://localhost:8080/mxclientsystem/mxui/mxui.js?637106200429445780:35:8625)
    at m (http://localhost:8080/mxclientsystem/mxui/mxui.js?637106200429445780:40:140472)