This issue is usually caused by the file associations being set incorrectly for opening .Switch attachments. In order to resolve the issue, we will need to ensure the Egress Client software is being used to open attachments.
The file associations can be changed by following the instructions below:
1. Navigate to 'Default Programs' in Control Panel
2. Select 'Associate a file type or protocol with a program'
3. On the list, navigate to .switch file
4. When .switch is highlighted, select 'Change Program..' and click 'Browse..'
5. Depending on the architecture of the machine, navigate to either 'C:\Program Files\Egress\Switch' OR 'C:\Program Files (x86)\Egress\Switch'
6. Select 'SDXCreator' and then 'OK'
If you can now try and open your secure email again, this should open successfully