We have an Excel template that contains a $[SUM(...)] expression that creates the sum over cells that are not connected (e.g the SUM is created over A1, A3, A5 and so forth and not continuously over A1, A2, A3 ...).
JXLS puts an Excel SUM function into the cell like "SUM(A1, A3, A5...)" (as opposed to "SUM(A:A)" when the sum is over continuous cells).
As long as there are not more than 255 Parameters within the SUM-function, all works properly. As soon as there are more than 255 cells to sum up, Excel fails with an error.
It would be nice if JXLS checks if there are more than 255 parameters and creates multiple SUM-calls (each with max 255 parameters) and adds them (e.g "SUM(A1, A3, A5...) + SUM(A256, A258, A260...)".