How to resolve “Type Not Defined” Error message in MS Access

An expression error message in MS Access primarily occurs when you attempt to create a new Microsoft Office Access Database Project (ADP) file or change the file size of Access database. Once the above error message occurs, the database freezes or becomes uncountable, making all the data stored in the database inaccessible. An ideal solution to overcome such data loss scenarios is by restoration of data from an up-to-date backup. But, in case of backup unavailability or backup falling short of restoring the required data, you will need to use advanced access recovery application.

Consider a practical scenario, where you encounter any of the below error messages when you attempt to mount your Access database (Employee):

"Type Not Defined"
Or
"The expression you entered refers to an object that is closed or doesn't exist"

Once any of the above error messages occur, the Employee database quits unexpectedly. Furthermore, when you attempt to remount the database, it does not mount making the data saved in the Employee database inaccessible.

Cause:

The root causes for the occurrence of the above error message are discussed below:

 Buggy Code
 Corrupt Database References

In case of database references corruption or damage, the operating system is unable to find the path and the database can not be accessed.
Resolution:

To resolve the above error and access the data saved in the database, you will need to follow the below measures:

 Redefine the Employee database reference
 If the problem persists, then it means that the Employee database has been corrupted.

In case of Employee database corruption, the first solution to repair the database is by using an inbuilt repair utility known as "Compact and Repair." The utility is competent enough to repair your database in most of the corruption scenarios. However, if the utility is unable to resolve the issue and the Employee database remains inaccessible, then you will need to use effective Access Recovery utility. Such Access Database Repair utilities employ powerful scanning mechanisms to completely scan and repair the corrupted database. Such applications can recover and restore inaccessible Access databases files (.mdb and .accdb).

Stellar Phoenix Access Recovery is the finest Access Database Repair application. It can restore and access repair database objects such as, tables, queries, forms, reports, macros and modules. The read only utility supports Microsoft Access 2007, 2003, 2002 (XP) and 2000. It is designed for Windows Vista, XP, 2003, 2000 and NT.