Core app freezing when trying to create a piston

Just reinstall CoRE (I deleted my hub location by mistake and lost my entire automation scheme), but the app freezes when I attempt to create a piston. I deleted the app in IDE and re-install it but got the same issue… (I’m fairly familiar with CoRE as i was running 20+ pistons before).
What’s going on? How can I resolve this issue?

I can’t give you a reason as to why this is happening but as you have to start afresh you might want to start using webCoRE. You can program via mobile or PC and it has more features including backup codes should you accidently delete and import other people’s to save you figuring things for yourself. It is worth it believe me.

Perhaps you can try going into core: settings: and reset security token and rebuild pistons? But I agree with @bobbles, you should really consider moving to WebCORE.