Crashes every time I use it – Xer+ Review

Please help me with this problem on program crashing every time we try and erase backgrounds of layers. My autistic son tried so hard to have success with your program on his ipad3 but to no avail. I paid for the full addition and can't use it for what you claim it to do. Please help us. Thanks
Review by The puzzler 99 on Xer+.