We CAN'T know the cause of the problem from the crash report , but it may be caused for some reasons :
1- A Huge lag spike which the Memory can't handle, the game crashes after that.
2- You use a unit/value which doesn't exist or you skip errors by JNGP if you work with JASS or Custom script GUI
What you have to inform us now is :
1- Are you using JNGP and you skip errors ?
2- Post the trigger of when the spell starts, (Right-click the trigger under the description box and click 'Copy as text' , and paste it here between Good luck