CoreTelephony Trace File error

Hello all,

After installing an SSD and using it as primary drive for my Macbook Pro (running El Capitain), after each restart I get a "CoreTelephony Trace File Error" with the above message:

A file operation for CoreTelephony tracing has failed, you may be out of disk space. Details 'Error opening file /tmp/ct.shutdown, err = Operation not permitted

Does anyone face the same error? I have already found some solutions, but they haven't helped for my case.

Any help will be much appreciated!