Errors: "An unhandled Microsoft .Net Framework exception occurred in toad.exe [14756]." and "Attempted to read or write protected memory. This is often an indication that other memory is corrupt." (4327525)

Toad for Data Analysts (TDA) crashes when doing a right-click Refresh Items in  Object Explorer | Views. Here is the Exception Information.

or

Toad Data Point (TDP) error as soon as trying to connect to database (Access).

ERRORS:

1)

An unhandled Microsoft .Net Framework exception occurred in toad.exe [14756].

2)

System.AccessViolationException was unhandled
 HResult=-2147467261
 Message=Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
 Source=System.Data
 StackTrace:
      at System.Data.OleDb.DataSourceWrapper.InitializeAndCreateSession(OleDbConnectionString constr, SessionWrapper& sessionWrapper)
      at System.Data.OleDb.OleDbConnectionInternal..ctor(OleDbConnectionString constr, OleDbConnection connection)
      at System.Data.OleDb.OleDbConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningObject)
      at System.Data.ProviderBase.DbConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions)
      at System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup, DbConnectionOptions userOptions)
      at System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection)
      at System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
      at System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
      at System.Data.ProviderBase.DbConnectionInternal.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory)
      at System.Data.OleDb.OleDbConnection.Open()
      at Quest.Toad.NativeOdbc.MSAccessAPIWorkaround.GetPrimaryKeys(NativeOdbcConnection connection, String tableName)
      at Quest.Toad.NativeOdbc.OdbcDriverWorkarounds.GetPrimaryKeyWorkaround(NativeOdbcConnection connection, String functionName, String TableName)
      at Quest.Toad.NativeOdbc.NativeOdbcConnection.GetPrimaryKeys(String owner, String TableName)
      at Quest.Toad.Odbc.Scheme.ColumnList.ColumnListTrl.GetPrimaryKeyList()
      at Quest.Toad.Odbc.Scheme.ColumnList.ColumnListTrl.GetTrls()
      at Quest.Toad.Odbc.Scheme.TableList.TableTrl.GetColumnTrls()
      at Quest.Toad.Trl.TrlExtensions.GetColumnTrls(ITrl trl)
      at Quest.Toad.DatabaseBrowser.ColumnListController.ColumnData_Processing(Object state)
      at System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(Object state)
      at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
      at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
      at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
      at System.Threading.ThreadPoolWorkQueue.Dispatch()
      at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()
 InnerException:

Data Execution Prevention (DEP) is preventing .NET application like Toad Data Point from working properly.

Add the 'Toad.exe' from TDP to the Data Execution Prevention (DEP) exception list. 

1.            Right click 'Computer' and click 'Properties' 

2.            Click the ‘Advanced’ tab 

3.            Click the ‘Settings’ button in the ‘Performance’ section 

4.            Go to the ‘Data Execution Prevention’ tab 

5.            Make sure the radio button labeled "Turn on DEP for all programs and services except those I select:" is checked 

6.            Click ‘Add’ at the bottom of the list 

7.            Browse to the executable (Toad.exe) and select it 

8.            Make sure the checkbox next to the executable name in the list is selected and click OK 

Refer to Microsoft KB Article 923028 - "FIX: Error message when you run a .NET Framework 2.0 Remoting application: "Unhandled Exception: System.AccessViolationException".