Work Offline is not possible because the offline store does not match the current online store.
The following MessageBox is displayed when working offline:
The offline store does not match the current online store. Please recreate the offline store.
To resolve this problem, the offline PST file relevant for this Outlook profile should be removed from the system and Work offline re-tried.
The location of the offline message store file must first be obtained; the offline PST file’s location is that of below.
Under Windows Vista and Windows 2008 Server:
%userprofile%AppDataLocalSoftalkSoftalk Share Server ClientOffline
Under other operating systems:
%userprofile%Local SettingsApplication DataSoftalkSoftalk Share Server ClientOffline
Navigate to the so determined folder and delete the PST file having the same name as the Outlook profile therein. That is to say, if the Outlook profile is called MyProfile then the PST file name will be MyProfile.pst. If the name of the profile is unknown, or there is only one profile, then the default profile will be named Outlook resulting in the offline message store being name Outlook.pst
Once the offline PST file has been deleted, work offline as usual by clicking File >> Work Offline from Outlook’s menu bar.