teensy loader does not open on mac el capitan

[automix]

Hello,

I hope you understand my very bad english. I can not open the teensy loader on my old IMac with El Capitan. Is there any other Software that do the job and runs on my old Mac ?

I have a NDLR on order from Schneiders Laden here in Gemany and I hope I can update it when necessary.

Best regards,
Frank