Hi Tomas,
In the SPARK GUI the "snapshot" is the same as "screenshot". This
option allows to save a picture of the current simulation state.
Probably, you are using an outdated version of SPARK where this
feature was not implemented completely. In the current version, it
should work.
Right now, it is not possible to save the simulation state in SPARK.
It was possible in older versions, but then the internal structure of
SPARK became more complicated and this feature was disabled. Saving/
resuming simulation state is very important, so this feature will be
implemented in SPARK soon.
Best,
Alexey