FAQS:

Q1: kArmTI crashes and I don't see any window anymore. How do I go about it?
A1: Please delete the following registry key: "HKEY_CURRENT_USER\Software\ScrapLab\kArmTI_v1.XY" 
   (where X and Y may vary, e.g. 'kArmTI_v1.07) and restart. This will restore 'defaults'.

https://www.omnimaga.org/ti-nspire-projects/karmti-ti-nspire-emulator-with-skin-16585