Q: What is a Rollback Inconsistency? (#6537)
<..> the data has become corrupted during a transfer, and is usually because one of the users, either you or the one you are downloading from, are using a bad firewall, such as ZoneAlarm intercepting some packets.
Q: How to set up active mode with a hardware firewall/router? (#6518) What about ZoneAlarm? Forget it. ZoneAlarm is a known issue with DC++, it causes corrupted downloads/uploads, this is directly linked with the 'Rollback Consistency' error message. You need to completely uninstall it, just disabling it will not help, and then get another firewall.