If a user encounters the error message shown below, they will need to disable developer mode in order to resolve the issue, here is the step by step process of how to do this.
1) Open Outlook
2) Select ‘File’ tab
3) Select ‘Options’
4) Select ‘Advanced’ tab in the Options
5) Under the ‘Developer's section untick the option ‘Show add-in user interface errors’ (see screenshot below)
This disables the developer mode of Outlook and should resolve the error message from appearing again.