# 4739 Updating Exclusively-Opened Tables Can Cause Corruption in the Session-Level Table Buffer Manager

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We are updating a main project from Berlin to Rio, when i found a bug in EDB.

In this sample application we create at runtime an EDBTable in a memory database, then pressing the button we copy all data of a non-memory table into the memory-table, then we load from disk some files into a blob field.

This exception is raised when we try to post the table after we loaded the file from disk into the blob field:

First chance exception at $75E0C6F2. Exception class EEDBException with message 'ElevateDB Error #601 The table tblStampe_Mem is corrupt (Invalid BLOB block type found)'.

We tried to assign the content of blob field not directly from disk but using a stream or a string too, and the exception is raised anyway, so the problem seems to be when the database saves the blob field and not during the LoadFromFile.
In addition after some different tries, we noticed that the bug is not present if the destination BLOB field is empty when we load it from file. If the destination BLOB field cointains some data when we load the file from disk it raises the previous exception.