Settings -> Alarms -> +Alarm -> Create alarm
The constraint that critical threshold must be greater than major is not correct. This constraint should be "greater or equal". For example.. in the case of Errors Per Interval, it's quite normal to have both thresholds set to 0, then to make the Critical fire on a greater number of periods over threshold.
Of course, this should be in context of the comparison operator. If the operator is "less than", the the constraint should be "less than or equal".
An enhancement requested was already raised in order to have it , will be evaluated and put in our backlog to be deployed soon.
To follow up on the status of this request, please raise a ticket on Broadcom Support Portal and refer to this knowledge article in order to get the status.