Workflows - tasks not being triggered. Alerts are working OK.

Workflows - tasks not being triggered. Alerts are working OK.

Hello. We have had a problem with workflows since approximately Friday 22nd January. Notifications are being sent but tasks are not being set. This has happened with at least 2 different workflows. I changed the tasks to come to my account, in case it was a problem with the user's account, but it still doesn't work.