Probe Basic facing no tool selected

how are you setting the tool lengths?

m6 Toolchange by hand, with a fixed toolsetter. I am not sure, but it works fine as long as the tool has not much more length then the tool before. Example: a 4mm mill with a length of 25mm first, then a 6mm mill with 50mm length, bumm joint 2 (z) exceed positive limit, what makes me wonder, the cnc has a z range about 240mm, the workpiece is 45mm high. After the error, w
hen i go to the home position(not homing!), it works.

yeah that sounds like you have some form of stacking going on maybe with tool length offsets maybe? i don't know, the main probe basic method work for repeatable holders, i tested it just yesterday while doing some work in the shop, so i know its not probe basic. I would investigate your tool setter subroutine and see what you have actually going on maybe.