Did you update your system?
In which case, update Luma by installing Lumaupdater here h%%ttps://github.c%om/KunoichiZ/lumaupdate/releases
(Delete the %s since I cannot yet send links)
Then head into FBI and uninstall the old NTR CFW completely (both title AND ticket)
Finally, install the latest release of BootNTR here h%%ttps://github.c%om/Nanquitas/BootNTR/releases/tag/v2.13.3
I updated my 3DS to 11.13.0 and everything seems to work now.
Please update if this solves your issue.