This error message show when you surpass maximum number of locks for a single file or number of columns in a table.
If you want increase the maximum number of locks per file, you need to modify a registry setting in your local computer.
How to Increase Maximum Number of Locks per File?NOTE : You need to have admin access (Run as Administrator) to be able to modify registry settings.
- Go to Start – Run... or Click Windows key +R
- Now type Regedit and Click OK
- Now Registry editor will appear.
- Navigate to HKEY_LOCAL_MACHINE ---> SOFTWARE ---> Microsoft --->
Office ---> 12.0 ---> Access Connectivity Engine ---> Engines ---> ACE
- Double click on "MaxLocksPerFile"
- In "Value data" modify value to 30d40 (Hexadecimal)
- Click OK
- Close Registry editor windows
Now you can change data type in microsoft office access 2007 without error messages. and your data types will be changed and properties will updated.