Electronic – Singular matrix warning

I faced some errors while trying to simulate a circuit. I tried to simplify it, but errors still stayed in place 😐

The following error message is what I get:

                    *************** PROCESS COMMAND ***************

/usr/bin/ngspice -n -b /home/rasakereh/Desktop/sharif/9602/EEC/test/test.ckt

                *************** PROCESS RESPONSE **************

Warning: singular matrix:  check nodes v3#branch and v3#branch

Warning: singular matrix:  check nodes v3#branch and v3#branch

Note: Starting dynamic gmin stepping
Trying gmin =   1.0000E-03 Warning: singular matrix:  check nodes v3#branch and v3#branch

Warning: Further gmin increment
Trying gmin =   5.6234E-03 Warning: singular matrix:  check nodes v3#branch and v3#branch

Warning: Further gmin increment
Trying gmin =   8.6596E-03 Warning: singular matrix:  check nodes v3#branch and v3#branch

…

Warning: gmin step failed
Warning: source stepping failed
doAnalyses: iteration limit reached

run simulation(s) aborted
Error: no such vector v(4)

Circuit: ********************************************************************************

Doing analysis at TEMP = 27.000000 and TNOM = 27.000000


CPU time since last call: 0.009 seconds.

Total CPU time: 0.010 seconds.

Total DRAM available = 7880.691406 MB.
DRAM currently available = 4678.652344 MB.
Total ngspice program size = 14.774414 MB.
Resident set size = 1.865234 MB.
Shared ngspice pages = 1.638672 MB.
Text (code) pages = 1.333008 MB.
Stack = 0 bytes.
Library pages = 404.000 kB.

I am using gEDA gscheme to generate the schematic, netlisting it using gnetlist and spice-sdb backend, trying to simulate it in gSpiceUi.

Thanks