Hi R lisboa, the kernel works just fine, the problem is making it work through the front end. In order to don't have to manually copy all my others nb in the server.

It is quite disappointing that in wolfram website there is not clear help about this problem.

Cheers Raf

I seem to have the same problem with Mma 7.0, and tried all what was recommended here, and more, to no avail. It used to work fine since years, but now after about 1 year of pause I noticed remote kernels "suddenly" don't work any more. AFAIK I didn't change the Mma setup in the mean time.

Here are the data:

-Problem happens for Mma 7.0 but for MMa 11.0 all is fine!

-Problem happens for any pair of two out of 3 machines.

-Machines run macOS High Sierra, 10.13.3

-passwortless ssh works between all machines

-I can run remote kernels via ssh

-I tried various setups using mathssh, tunnel.sh

-The following errors appear immediately, so it seems likely that the error is with the frontend and not with the connection:

-setup using mathssh yields: "The kernel xxxxx failed to connect to the front end. (Error = MLECONNECT). You should try running the kernel connection outside the front end."

-setup using tunnel.sh: yields panel with "Mathematica could not establish a connection to the kernel. Kernel: Local. Low-level MathLink error: Unknown internal error."

-I suspect it may have to do with Java, there were some other problems in the past with Java and Mma.

Any help?

Thanks!