Some examples include not being able to:
i) book stock into any warehouses
ii) pick any stock
Make sure that no one is processing any stock transactions ask the user with issues to try again.
If that does not work, try clearing users slots:
System
Maintenance
User Slots
Select Delete All (that will only remove inactive slots)
Yes to Delete
If that does not resolve the issue it needs to go to ASC support to investigate
