This error appears in payslip edit form, this is for your action
Please do not divert topics with unrelated questions. That reduces your chance of obtaining assistance. I have moved your last post to a separate topic.
I can reproduce this. Any zero quantity seems to produce an incorrect result regardless of number format. Further, if the number format is 123.456.789,00, non-zero entries produce errors.
I am putting this into the bugs category. It seems related to others just moved to that category. This was reproduced with version 18.10.0.
Thanks for your quick answer.
Fixed in the latest version (18.10.2)