If you receive an error, Max locks per file when trying to upgrade your access database in checkmate 5.1, please try the following.
1. Quit Checkmate.
2. Click Start and then click Run.
3. In the Open box, type regedit.
4. Locate the HKEY_LOCAL_MACHINE registry folder.
5. Expand HKEY_LOCAL_MACHINE until you locate the SOFTWARE\Microsoft\Jet\4.0\Engines\Jet 4.0 folder.
6. Click on the Jet 4.0 folder to view its contents.
7. Select the MaxLocksPerFile entry; on the Edit menu, click Modify.
8.
In the Edit DWORD Value dialog box, select Decimal and increase the
number in the Value Data box. Make it twice bigger as the first step,
then you may increase it further if not enough.
9. Click OK to save the MaxLocksPerFile setting.
10. Quit the Registry Editor.
11. Start Microsoft Access and synchronize the replicas.