Error saving the document to a temporary file

Hi there,

we always get the error: "Error saving the document to a temporary file / Message no. SOFFICEINTEGRATION170" when we open a text editor in SAP. (Office editor)

Example: PFTS -> Standard task: 90100091 -> Description and then view the description with the text editor.

We have installed Microsoft Office 2013 Standard.
SAP GUI 740 PL 5 Hotfix 2

When I start the SAP GUI with an admin user everything works fine.

Do you know anything about this error and how we can solve it?

Thanks in advance.
Lukas