Sometimes tier tools (like Word or Excel) open an unexpected dialog while the export is running.
Since the tool is opened in the background, the dialog is not often visible.
To unblock this, look for any suspicious program in the task manager "applications" tab.
- Word can ask for confirmation to convert RTF format. See how to fix this here.
- Excel can stop the process if you are in edit mode inside an Excel cell
- Excel can also prompt for confirmation if you are trying to import an already existing file