# Invalid MIT-MAGIC-COOKIE-1 keyNote when working with mpirun

After installing QUANTUM ESPRESSO on a i7-laptop I tried to do a scf calculation to see if the QUANTUM ESPRESSO works. I got an output, and the results seems to be OK. However, there is an error that appears in the terminal. It is annoying that it will appear in every calculation I do and also I dont know if that error affects my calculations. The error appears like that

/Desktop/folder\$ mpirun '/homeDesktop/qe-7.0/bin/pw.x' -in scf.in> scf.out
Invalid MIT-MAGIC-COOKIE-1 keyNote: The following floating-point exceptions are signalling: IEEE_DENORMAL
Note: The following floating-point exceptions are signalling: IEEE_DENORMAL
Note: The following floating-point exceptions are signalling: IEEE_DENORMAL
Note: The following floating-point exceptions are signalling: IEEE_DENORMAL
Note: The following floating-point exceptions are signalling: IEEE_DENORMAL
Note: The following floating-point exceptions are signalling: IEEE_DENORMAL
Note: The following floating-point exceptions are signalling: IEEE_DENORMAL
Note: The following floating-point exceptions are signalling: IEEE_DENORMAL


Can anyone help me to fix this, please?

• Did you compiled QE for running in parallel?
– Camps
Feb 1 at 19:36
• After installing Quantum Espresso I installed mpi to be able to work in parallel environment . To install the mpi I used the command : sudo apt-get install openmpi-bin openmpi-doc libopenmpi-dev Feb 1 at 22:39
• This is problem of display driver in newer version of ubuntu. either switch to gdm3 or just ignore the error and keep working Feb 2 at 2:10
• Im using ubuntu 20.04 Feb 3 at 10:13

Invalid MIT-MAGIC-COOKIE-1 key is to do with X permissions, and has been reported elsewhere, https://www.reddit.com/r/linuxquestions/comments/njfvoq/invalid_mitmagiccookie1_key_when_running_mpi/ for example, when using openMPI and certain flavours of Linux, mostly more modern versions of Ubuntu and variants thereon. Ignore it.
Note: The following floating-point exceptions are signalling: IEEE_DENORMAL is telling you that your calculation produced some sub/denormal numbers. This is typical and almost certainly harmless. Ignore it.