Board Thread:Help desk/@comment-31852616-20170427194020

Recently, I got to the part in story where i need to complete ho-oh's challenge. I wasnt strong enough so i started grinding my pokemon for awhile. Then when i had my Pokemon above 65-70 lvl range I went to try and do challenge again except this time some flash happens on my screen every few seconds and does damage to my whole team. Also, during every battle since then it does the same thing. I can't even play anymore because of it. Does anyone know what happened?  