On singleplayer i have no problem, but with my modded 1.7.10 forge server i cant connect to the server if chisel is installed. The client log says because of the missing block smashingrock. Without chisel i cant connect.
chiselproblem.txt
I tried three different Versions of chisel, including 2.9.5.11 for MC 1.7.10, every time the same problem.

You must have that item disabled in your client. 1.7.10 is not supported, either way.

Ok, i found a workaround by myself: I set
B:smashingRock=false
in the chisel.cfg file and it worked. Now i can use this great mod with its marble and various stones on my server :)

Just saw you answered already, thanks ;)