Some customers has experienced, that when issuing invoiced an error has occurred with that It can't divide with zero.
This happened because the Invoice frequency was blank. In relation to the version 21.0.202242.46983, the information has been moved to a new field- in order to handle period (M,W,Y) across language codes. Unfortunately some customers has experienced that the upgrade when wrong.
If you experience this issue- please contact the Abakion Support and we can help with a manual update. They can be contacted on: firstname.lastname@example.org.