Hi, I have a workflow where I want to check each line on a transfer order to check if a checkbox is selected on that lines items related item record, I have used an sublist action group on the items sublist and set it to return user error if the tickbox in question isn't checked, however it never triggered. I have then set it to return a user error and put the variable into the text field that would show the value of the checkbox and it displays blank. is there a limitation stopping you from accessing line.item.custitem_customcheckbox for example?

Not aware of a limitation. I would take a step back and make sure you have the Workflow set correctly for triggering in any case. I usually start by writing something to the memo/description field without criteria. The start to work with your criteria still updating the memo. The finally add your popup. BTW it's not clear what trigger you are trying to use .

The test user error i added with no condition was firing off correctly just with empty field values, i've tried using a few different trigger points, at this point to no avail. the basic flow is add a button to the record, when its pressed it needs to cycle through the items, check they all have the appropriate tick on the item record and if so check a box on the TO record, otherwise display a user error as soon as it finds a problem