When you use Lync or Skype for Business, you can save your conversations in your Outlook data file. To do this, Lync needs to access your .ost file. Under normal conditions, this process works very well and goes unnoticed.
If, when Lync is running, you are receiving errors stating that you don't have permission to access the file when you try to open appointments or email messages, you need to check the compatibility mode settings for both Outlook and Lync.
If the compatibility settings are correct (as compatibility is not turned on), you can disconnect Skype of Business from Outlook.
When attempting to view Calendar:
Cannot display the folder. File access is denied. You do not have the permission required to access the file C:\Users\username\local settings\application data\microsoft\outlook\outlook.ost.
When attempting to open a message:
Cannot open this item. File access is denied. You do not have the permission required to access the file C:\Users\username\local settings\application data\microsoft\outlook\outlook.ost.
If you stop Lync, the error goes away and you open the message or calendar without a problem. When you restart Lync, the problem eventually returns. If you wait a bit (maybe 5-10 minutes), the problem may go away on its own.
There are three possible causes/solutions for this behavior:
- The Lync shortcut or application is configured to run in Windows XP SP3 Compatibility mode.
- You may receive this error if you have Lync set to run as administrator.
- Skype for Business (Lync) is connected to Outlook and accessing the .ost file.
There is no reason to use compatibility mode with Lync. Compatibility mode should be used only with old programs.
Change Compatibility Settings
Check Compatibility Mode Settings
- To disable Compatibility mode or confirm its not enabled, right click on the Lync shortcut, then select Properties.
- Click the Compatibility tab in the Properties dialog and uncheck the Compatibility mode box that says "Run this program in Compatibility Mode".
In most cases, it won't matter if you use the run as administrator option, but it also should not be enabled permanently (for most users). We recommend disabling run as administrator (if enabled).
We have a video tutorial at How to Disable Compatibility Mode in Outlook. While this shows how to disable it in Outlook, the process is similar for other applications.