SQL Server is surrounded with many technical rifts and these can put you in database inaccessibility issues. SQL Server error 2515 is another such error which can make the database inaccessible and requires proper mechanism to solve the issue. Error appears to be;
Severity Level: 16
Error Message Text:
Page P_ID, object ID O_ID, index ID I_ID has been modified but is not marked modified in the differential backup bitmap.
Table Error 8988: Row (%d:%d:%d) identified by (%ls)
The above mentioned SQL error 2515 shows that the page is having an LSN which is higher than the differential reference LSN recorded in Backup Manager but these changes has not been recorded in the differential backup bitmap. LSN is basically a log sequence number which is provided to all the records in SQL Server transaction log to attain a unique identity. These LSNs are sequentially maintained in such a way that if LSN2 is greater than LSN1, then the change associated with LSN1 will occur before LSN2 in the log records.
In order to make the database accessible without any SQL error code 2515, one has to take necessary steps. You can try following steps in order to make the SQL database error-free:-
All these above mentioned steps can be tried for recovery of database and eliminating root cause of the SQL Server error 2515. If all these methods fail to do so then it clearly indicates that the database has some serious issues and needs a liable solution. In such situation it is recommended to use professional third party software like SQL MDF file recovery software in order to recover database without any scope of failure.