Users are unable to select a service provider when creating or editing a notification device in the user preference windowDescription<!-- div.margin{ padding: 10px 40px 40px 30px; } table.tocTable{ border: 1px solid; border-color:#E0E0E0; background-color: rgb(245, 245, 245); padding-top: .6em; padding-bottom: .6em; padding-left: .9em; padding-right: .6em; } table.noteTable{ border:1px solid; border-color:#E0E0E0; background-color: rgb(245, 245, 245); width: 100%; border-spacing:2; } table.internaltable { white-space:nowrap; text-align:left; border-width: 1px; border-collapse: collapse; font-size:14px; width: 85%; } table.internaltable th { border-width: 1px; padding: 5px; border-style: solid; border-color: rgb(245, 245, 245); background-color: rgb(245, 245, 245); } table.internaltable td { border-width: 1px; padding: 5px; border-style: solid; border-color: #E0E0E0; color: #000000; } .title { color: #D1232B; font-weight:normal; font-size:28px; } h1{ color: #D1232B; font-weight:normal; font-size:21px; margin-bottom:-5px } h2{ color: #646464; font-weight:bold; font-size:18px; } h3{ color: #000000; font-weight:BOLD; font-size:16px; text-decoration:underline; } h4{ color: #646464; font-weight:BOLD; font-size:15px; text-decoration:; } h5{ color: #000000; font-weight:BOLD; font-size:13px; text-decoration:; } h6{ color: #000000; font-weight:BOLD; font-size:14px; text-decoration:; } ul{ list-style: disc outside none; margin-left: 0; } li { padding-left: 1em; } --> Symptoms Users are getting Security constraints prevent access to requested page error when trying to select a service provider on creating or editing a notification device in the user preference window Cause The active service provider (cmn_notif_service_provider) records number has surpassed the specified value on the system property glide.ui.max_ref_dropdown causing the reference field to become a normal reference field from it being a drop-down type. Resolution There are several solution options as per below that could be applied for this issue: Reduce the number of active cmn_notif_service_provider so it is 25 or less, orIncrease the number of the system property glide.ui.max_ref_dropdown, orCreate the appropriate table level read ACL on cmn_notif_service_provider so even if the reference field turns into a normal magnifying glass users would still have access (as long as they pass the ACL) Additional Information glide.ui.max_ref_dropdown has this description:"Maximum number of records allowed for a reference field displayed as a choice list. If more records than this are available, default reference field UI is used." This is the expected platform behavior: When reference fields are loaded as a dropdown, an unprivileged user can see them regardless of ACL.When there are enough references (meaning the active records surpassed the number specified on the property) it does a lookup that does respect ACL (so if no ACL is specified non-admin users will fail access by default).