Task Scheduler: Task unable to connect to network?

I have a Task Scheduled to run at 1am (backup data to a network drive). The first night after I created the task, it ran fine. But then the following three nights, it failed and indicated that it couldn't connect to the network.

I've found this after getting up in the morning and started my laptop up. The network connection is fine when I get up.

Why would it be unable to connect the past three nights but it worked fine the first night and also works with no issues when I wake up in the morning?

TIA!

Welcome
Make sure that the task is set up properly
http://www.vistax64.com/tutorials/132903-task-scheduler-create-task.html

and

You may need a task to wake the computer
http://www.vistax64.com/tutorials/166809-task-scheduler-wake-up-computer.html

It's set up to wake the computer. It did attempt to run--the task history indicates that it couldn't connect to the network. That's why I asked what would prevent it from connecting to the network.

Go to search type event viewer and look for possible causes at the time the task was suppose to occur.