Someone gave you the 'frogs' gesture, normally it is even given as frogs.vpa. This gesture crashes VP when saved in the exts\gestures directory or when you change to the folder where it is stored as being your gesture folder.
You need to delete this gesture in order to be able to use VP again.

Best way is sort the gestures in your gesture folder by date and delete the latest ones or move them (only when in your gesture folder will they crash VP) until VP works again.

Now you can save yourself against this sick game people play with newbies: Download and install the Anti-Boot-Gesture-Patch. (Click on patches) Note that this patch is not a 100% security.

So how can you protect yourself from boot gestures efficiently?

Well, easy, dont download any.... no not at all but not in your gesture palette. Open a second one, for testing,
test the gesture there, and if it is OK move it to your real one. If it crashes you can quickly find out what gesture is the
bad one and dealing with a few palettes isnt too hard.
If you crash, remember to change the palette before you log in or to delete the bad gesture. Otherwise you can count the seconds until you crash again.