Calculation works while testing, but result cannot be written to database

Hi, I have a general problem with calculations in Calc: Even if the calculation runs smoothly when I test it, I get an error in step 3 when running the calculation chain. Obviously the results are not written to the database. I also see that the plot area is not written to the tree view (even if correct). My simple example calculation is: tree$tree_basalarea <- pi/4*(tree$tree_dbh/100)^2 I am using a test case with only some trees. The error I get is: Error in 'tree basal area' org.openforis.calc.r.RException: R error while evaluating tree basal area at org.openforis.calc.engine.CalcRTask.execute(CalcRTask.java:58) at org.openforis.calc.engine.Worker.run(Worker.java:75) at org.openforis.calc.engine.Job.execute(Job.java:103) at org.openforis.calc.engine.Worker.run(Worker.java:75) at org.openforis.calc.engine.Job.run(Job.java:89) at org.openforis.calc.engine.TaskManager$1.run(TaskManager.java:232) at org.springframework.core.task.SimpleAsyncTaskExecutor$ConcurrencyThrottlingRunnable.run(SimpleAsyncTaskExecutor.java:230) at java.lang.Thread.run(Thread.java:745) Error in `$<-.data.frame`(`*tmp*`, "tree_basalarea_per_ha", value = numeric(0)) : Ersetzung hat 0 Zeilen, Daten haben 3 Error in checkError(result, connection) : Error in `$<-.data.frame`(`*tmp*`, "tree_basalarea_per_ha", value = numeric(0)) : Ersetzung hat 0 Zeilen, Daten haben 3