To delete a single transition:
In the Project browser, select the transition icon, and then press Delete, or choose Edit > Delete Selection.
(There are many styles of transition icons; several are shown below.)
If automatic transitions are turned on, click Turn Off Automatic Transitions in the dialog that appears.
The selected transition is removed, and you can now add, delete, and change existing transitions in the project however you want.
To delete all transitions:
Do one of the following:
If your project has no theme and doesn’t have automatic transitions, choose Edit > Select > Transitions, and then press Delete.
The Edit menu appears in a light gray bar across the top of your computer screen.
If your project has no theme but does have automatic transitions, choose File > Project Theme, and deselect the “Automatically add transitions” checkbox. Then choose one of the following options:
Remove transitions and extend clip ends: Removes all transitions from the project and slightly extends the ends of the clips that were adjacent to the transitions. This options lengthens the duration of your project a bit.
Remove transitions and maintain clip durations: Removes all transitions from the project and slightly shortens the ends of the clips that were adjacent to the transitions. This option maintains the current duration of your project.
If your project has a theme, choose File > Project Theme and deselect the “Automatically add transitions and titles” checkbox.