An error happened during restoring the context for requested location (SBL-UIF-00313) Open ui

Getting this error intermittently in IP 16 deployment. I found references to this issue in Knowledge base, but they seemed to all refer to earlier (pre-open ui) versions of Siebel, some of which indicated they were fixed in patch <patch number earlier than IP 16).

Is there any information on what might be causing this now? It is not easy to replicate, as it only seems to come up every so often. However, when it does, it appears the only way to get out of it is to close the browser and start again, since the error pops up no matter what you try to do in your popup or pick applet, including click the ok, close, or cancel button. Therefore, you can't close it.