DAE -87 is primarily a drive-related error. In the old days of Pro Tools, it referred to SCSI transfer rates. The typical cause was a disk that was either too full or too fragmented, or an invalid SCSI drive in the mix. These same issue can happen today, although under different forms. For example, disks that are too full/fragmented usually give different errors (-9073, -9019, -6085, -9094, etc.). Additionally, since SCSI drives are no longer in common use, these are translated as file system errors. In essence, the primary cause of DAE -87's is a disk that is incorrectly or inefficiently streaming data. This can be caused by several things:

- A disk mounted inside another disk (see KB# 30002).
- A formatting or file system error. Re-formatting the hard drive will fix it in this case. Do not use a quick-format option; spend the extra time and do a full format. Remeber to back up before formatting!
- Disk too full or fragmented (again, uncommon but possible). Remove some data (KB# 30105) and/or defragment the drive.
- Bad hardware. Try replacing the drive cabling. Also, try the session from another drive. If it works with no errors from another drive, the original drive could be going bad and need replacement. If they are still present when accessed from multiple drives, there could be a problem with the system drive.

In the event of suspected drive malfunctions (i.e., bad hardware), the best thing to do is run a diagnostic utility. Each drive manufacturer will have a utility available for download.

If none of these solutions solves a DAE -87 error, please call Tech Support.