Hi, After our recent deployment we get quite a few messages in our log like: 2013-03-08 10:14:50.885 ERROR - Connector: la: requirement failed: Change object 'GenericObject' should not be null at ExchangeClientAddition.Attachment_Save (Change : 'Change 'GenericObject' (AttachmentSize, AttachmentInfo)') The log entries refer to several different microflows and seem to be caused by Parameters/Input objects not being present in the Microflow. E.g. Microflow A has a (1) parameter Organisation, in the first action in the microflow we use a Exclusive split to evaluate the Organisation object and we get the error. I do see the messages in the log but cannot reproduce it. In some cases it seems that popup forms seems to lose the 'connection' with the main form/object from which they were called. How can we prevent these issues from occuring? Did anyone experience this? Brian Two remarks: Although we advice to not do it, some users seem to open their application in more than 1 tab in 1 browser window. So several windows sharing the same session. Can this possibly cause issues like this? When testing, I managed to open a popup (opened from a form using a dataview Object A and an enclosed datagrid (Object B) new button) which normally displays the name of Object A, without the name of A being displayed. It is very hard to reproduce though and seemed only possible since the main form was not fully loaded yet (I had to click rapidly). I logged a Service Call with Mendix Support. ID's seem to disappear causing empty objects. Pending research. First step will be an upgrade to 440.
Add empty checks before doing the real changes, which check on $organization = empty
Having the same application open in multiple tabs can cause issues like this yes.
What can also cause issues like this is to have a datasource microflow on a dataview that is shown or hidden using conditional formatting. However, i have to agree with michel there adding some empty checks is almost always a good idea. Since you cannot be sure when the parent object is actually filled.