Suddenly unable to move path handles of Mask Path

[RickAW]

I have been editing the position of a simple rectangular Mask Path within a Mask object. Select handles, move them to new locations, set a keyframe, repeat. It was working fine for several keyframes, then something changed.

I am now able to select and deselect the handles, but they will not move with either the mouse or arrow keys. Both methods were working fine previously. I cannot edit keyframes I already created. I can't detect anything that is different in the UI.

Is there a lock setting? Did I click a button or hit a key command that disabled editing? If I create a new object, its handles can be moved as usual, but not the existing rectangle.

[Dave_LaRonde]

Did you inadvertently make a new mask?

[Roland Kahlenberg · Accepted solution]

A mask can be locked in AE. A layer too can be locked. However, if a layer is locked, you will not be able to select the layer or any of its control points in the Comp Panel and you will not be able to change any of its properties in the Timeline. If a mask is locked, you will not be able to see it's vertices.

The only plausible explanation is you have created an Expression to link this Mask's Path to another Mask Path AND you've also linked their Transform properties. This seems unlikely.

I can only suggest that you start anew instead of trying to fix this issue - sometimes, it's better to start from scratch instead of trying to solve strange, out of this world issues.

[RickAW]

That's the approach I took -- reverted to a previous file and started over. The problem did not recur. Thanks!

[Ian231395630igw]

hit f4

[JonahSamuel]

Not sure if this is the same issue that brought me here, but: Instead of selecting, e.g., [Layer] > Masks > Mask 1, go back a level and select [Layer] > Masks. 

For whatever reason, this changes the state of the mask vertices from "joined" (square) to editable (round). 

[defaultmoyvev99xg7g]

This is what worked for me, thank you!