1.- Your issue got *nothing* to do with DLLs (it's just about new messages in SL's servers and is totally harmless).
2.- Make sure you are using the *latest* release of the Cool VL Viewer (messages have been added to SL servers that old releases don't know about).
3.- If you did install one of the latest releases (v1.26.4.46, v1.26.6.5 or v1.26.7.2) and still got unknown messages issues, then please provide a *proper* bug report with logs. See the
rules.