Don't know if it's just me, my system or the internet, but quite frequently while farming (especially prunning/removing bugs) I get a message "Gathering Time is Invalid". If I wait a few seconds, it usually allows me to perform the task, but sometimes I get the message several times. 

Thank you for giving us feedback on the issue. We are aware of the current optimization issues and we are hard at work to clear them up, thank you for your patience. I will be forwarding your feedback to the devs to help assist in fixing it!! :)