Parts opening as read-only

I'm using SolidWorks 2016 SP1.0. If I'm creating a part or assembly, I save the part, close the part and reopen. When it opens back up it is read-only. It thinks the file is open by another user. I have to close it, close SolidWorks, Open solidworks and open my file. I will then be able to edit and save like normal.

I didn't have this issue before updating to 2016.

Any idea as to what is the problem?

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