How to subtract time(t) data from time(0) data

Heyo,
I have to restart the discussion here.
I am trying the above, but paraview keeps crashing when I apply the Python calculator.

One difference I have, is that I am dealing with CellData. But that shouldn’t make a difference, right?

Another way I tried also did not work:
Importing group of data (this i the time-series of cellData)
importing the data(t=0) and use the calculator to rename the “arr” as “base”/ or use the ForceTimeFilter
then use append datasets to combine data (of all time steps) with the calculated “base”
then use the “normal” calculator filter to subtract arr - base --> then my timesteps are lost, an the operation is only done for the first time step, which results in diffences of e-38, which I guess is the computational precision limit

Any suggestions?
I am using PV 5.4.1 on Ubuntu 18.04