If you do not use VDUI module, then XForms works fine, and vise versa. both modules can not be used together. I feel it is the obs type used in VDUI which overlaps with XForms.
if you upload the Visit Documents UI module then upload a file in an active visit. then this issue will be created.
Open the below link then see the visit notes. http://qa-refapp.openmrs.org/openmrs//coreapps/patientdashboard/patientDashboard.page?patientId=2427&visitId=6791#