Same here. APC Smart-UPS 620I on RS232 in RB450G Same here. v5.19 UPS package works fine, but not in v5.20. Put everything back to v5.19 and UPS is good and working. Need this fixed! Thanks! Brad When i try to add UPS - The following errors: "Couldn`t add New UPS - opening serial port failed: ...

UPS doesn't work with 5.20.
With 5.19 it works very well.
Is there something wrong?

"Couldn't change UPS <ups1> - port's channel is already in use (6)"

The same configuration but with RouterOS 5.19 works fine.

Can you help me?

Thanks.