heap corrupted : non-matching sizes :-22904..13041
This sometimes happens when some revisions of the APC Masterswitch OS have too much uptime.
The issue can be temporarily resolved by rebooting the management card. Even though your terminal is filling up with these errors, you can still actually log in and reboot the card - you just have to do it semi-blind.
For some revisions of OS, the key sequence is:
3 (the 'System' menu)
5 (the 'Tools' menu)
1 (the 'Reboot' option)
YES (all in caps, to confirm that you want to reboot)
This will clear the error without power-cycling any devices. I suspect that an OS upgrade would address the issue permanently.