On certain occasions, a user can experience trouble while opening or saving an email attachment in Microsoft Outlook. The issue mainly occurs when the Temporary Internet Files folder is stored on a server to which a user has restricted access or insufficient permissions. The troubleshooting steps described below can help you resolve the issue. The exact error message you receive could be:
Cannot save the file, Cannot create file. Right-click the folder you want to create the file in and then click Properties on the shortcut menu to check your permissions for the folder.
Cannot open or save Email Attachments in Outlook
If Outlook fails to open an attachment displaying ‘Cannot create file‘ error message then, you have one of two problems. Your temporary file folder is either full of other files of the same name, or you do not have the correct permissions to save to that folder on the server. Here’s a way to fix it.
Launch File Explorer and open the C DRive. Create a new folder named tempoutlook here.
Open Registry Editor by pressing Win+R simultaneously. Type regedit and hit Enter.
Now, locate the following registry key:
HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Security
In the right pane, double-click OutlookSecureTempFolder.
In the Value Data field, type C:\tempoutlook\ and then click OK.
Exit Registry Editor and restart the computer.
It should help!
Also, if you can no longer attach files to (some, but not all) plain text emails in Outlook 2016, try this fix. Click on the Format Text menu item and select HTML. Oddly, this solution is known to work in many cases. Sometimes troublesome emails that do not allow users to add attachments are, in fact ‘Plain Text’ emails.