When you work on a worksharing Revit project you work within a copy of a central file.
You then periodically save you changes back to the central file by using the Synchronize with Central command.
This command also loads any changes made by others (if they saved back to the Central file) into your local file.
As long as changes have been Synchronized with Central, Local files are not only disposable, but need to be recreated on a regular basis.
Why you need to keep your local file up to date
If you do not Synchronize with Central regularly you may end up creating things that somebody else has already created, or making changes to things that have been changed or deleted by others.
If the central file has been compacted since you last created your local file it is possible Revit will refuse to save changes made in your local file back to the central file.
Refer to PROTOCOLS>MODEL MANAGEMENT>MAIN CENTRAL FILE.
In cases of extremely old local files Synchronizing with Central can lead to a corrupt central file.
Create new Local Files Regularly
From AutoDesk (Revit Help):
"It is good practice to create a local copy of the central model every day."
To be sensible about it, you don’t need to create a new Local file every day if you are constantly working in the file (and synchronizing with Central).
But if you haven’t worked on a file for more than a day (24 hours), make sure you create a new Local file before starting work.
Procedure to Create a Local File from within Revit
The correct procedure for creating a Local file:
Open>Project (use command from top left R so you get a dialog box).
Browse to the Central File.
Make sure Create New Local is ticked.
Note: If you select Detach from Central, then Create New Local will be cleared.
Clear both options to open the central model itself instead of a copy (which you should NOT be doing).
Click Open button.
Revit will create a new Local file by copying the Central File.
It is copied to the path set in Options > File Locations tab > Default path for user files.
It will be named the same as the central file with your username appended to the end of it.
Revit uses the user name set in Options > General tab > Username, NOT your Windows user name.
If want your local file in a different location and/or file name use Save As.
If you open a local file instead of a central file the Detach from Central tickbox will be greyed out.
If you are already working in the central model, use Save As to create a local copy.
If you are working in a local file and try Save As the Detach from Central tickbox will be greyed out.
Procedure to Create a Local File outside of Revit
You can create new Local files by making a copy of the central file using Windows.
Usually you would copy it to another folder and rename it.
This procedure can be automated using windows batch files, and may be more convenient than opening and closing files in Revit.
There is a batch file to do this in S:\Revit Settings\Batch Files called !MakeLocal_RevitFile.BAT.
This can either substitutes characters in the central file name with your windows user name (i.e. your log on name), or add your name to the end of the central file name. By default it substitutes the word 'central' with your user name.
To use the batch file:
Copy the batch file to the folder where you want to save your local file (for each project).
If you have multiple projects in one folder you will need to rename the batch file for each project.
Right click on it and select Edit.
Change the name of the central file and central file path to match the project.
If you DON'T want to substitute 'central' in the central file name make the necessary changes.
Save and exit.
When you want to create a new Local file, just double click on the batch file.
After is has successfully copied the file you have the option of opening the new file in Revit.
When you open the copied file in Revit it is recognised by Revit as a Local file.
The following dialog box will be displayed when you first open the copied file:
Just hit the Close button and keep going.
Don't Rename or Move a Central File
If you rename, or move, a central file in Windows Explorer Revit local files will not be able to find it.
Revit keeps it's own record of the central file name and path.
If you want to rename or move a central file use Save As from within Revit.