How do I copy-paste tasks from another excel file or worksheet?

Assuming you have created a Gantt Chart in the Gantt Excel Template... Here are the steps.

1. Backup and save your file.

2. First copy and paste tasks as values and then copy over dates.

3. Copy-paste should be done one column at a time starting with the task column.

Note - It is very important to paste as values. Please note WBS is automatically calculated.