What KiCad version are you using?
What is your operating system?
Application: KiCad
Version: 6.0.5+dfsg-1, release build
Libraries:
wxWidgets 3.0.5
libcurl/7.68.0 OpenSSL/1.1.1d zlib/1.2.11 brotli/1.0.7 libpsl/0.20.2 (+libidn2/2.0.5) libssh2/1.8.0 nghttp2/1.39.2 librtmp/2.3
Platform: Linux 5.16.0-1-amd64 x86_64, 64 bit, Little endian, wxGTK, i3, x11
Build Info:
Date: May 19 2022 15:05:13
wxWidgets: 3.0.5 (wchar_t,wx containers,compatible with 2.8) GTK+ 3.24
Boost: 1.74.0
OCC: 7.5.1
Curl: 7.83.1
ngspice: 36
Compiler: GCC 11.3.0 with C++ ABI 1016
Build settings:
KICAD_USE_OCC=ON
KICAD_SPICE=ON
What did you enter in the GUI?

What is the KiCad/ngspice reaction (any error message, any othe message …)?
Instance: a.xu11.a0 Message:
ERROR
D_STATE: failed to open state file.