Hello,
This issue happens any time you go into the ninja assist interface after doing infinite illusion during your game session (even if you just swept). Unfortunately, this has not yet been fixed, and the only workaround is to refresh your game. Fortunately, refreshing the game seems to have a 100% fix rate, so you'll have no issues once you refresh.
Thanks!

Hello, at least I'm not the only one with such game problem. It started this week. My game has became very slow. I find this out while making teams for Ninja exam. Even if you do daily, you need to wait longer time for events to load. It started after 18.05. Its not only this game, but other games I play too and the Internet. Its slower from that date. Even if I clean my pc or game it wont help. Please, help me, us out.

Dark Karera, it looks like you most likely have an internet issue, or possibly a virus. If it's regularly happening at 18:05, that's probably peak bandwidth time, so internet issue. You may need to contact your ISP to get the issue resolved. If you have a virus, I would suggest looking into methods for virus removal.
Either way, you will need to look to search for a solution on those topics or any other symptoms you may have, and we may not be able to help you since your issue seems to not be specific to this game. Also, in the future, please start your own thread for any queries or issues, rather than derailing someone else's thread.