After disabling ISAM key buffers, reading a record using an index, then re-reading the record, if an update then caused the record to move, a call to read the next record could fail with error 160 or return the wrong record.
Note: This issue only affected applications that use the option to disable ISAM key buffers with code that supports automatically refreshing the ISAM key buffers when needed. This feature is enabled in V10.4.1 and later.
The logic has been modified to eliminate this problem.