bluetooth trackpad stopped working after service update OSX

I have an imac with a trackpad 1 wich was working oke until after the update it does not responded anymore. I tried other trackpad and a bluetooth keyboard. nothing works. Then i tried the same trackpads on other computers with the following result: Mac mini 2012 no problems. Macbook pro 2009 same problems.

Can the update have changed something so that older mac no longer function with bluetooth trackpad?

Greetings David