Unfortunately, that is all what appears on the screen. From the server log files:
10/05/2011 11:57:50 AM HTTP JVM: CLFAD0211E: Exception thrown. For more detailed information, please consult error-log-0.xml located in E:/Lotus/Domino/data/domino/workspace/logs
10/05/2011 11:57:50 AM HTTP JVM: CLFAD0246E: Exception occurred servicing request for:/xblog.nsf/default.xsp - HTTP Code: 500. For more detailed information, please consult error-log-0.xml located in E:/Lotus/Domino/data/domino/workspace/logs
10/05/2011 11:57:51 AM HTTP Web Server: Command Not Handled Exception [/xblog.nsf] Anonymous
From error-log-0.xml:
SEVERE
com.ibm.designer.runtime.domino.adapter.LCDEnvironment
doService
java.lang.RuntimeException: com.ibm.xsp.FacesExceptionEx: java.lang.Error: Unresolved compilation problems: 
	The import com.ibm.xsp.extlib.resources cannot be resolved
	The import com.ibm.xsp.extlib.util cannot be resolved
	ExtLibResources cannot be resolved
	ExtLibResources cannot be resolved
	The method addEncodeResource(FacesContext, DojoModuleResource) is undefined for the type XBlogResources
	ExtLibUtil cannot be resolved

	at com.ibm.designer.runtime.domino.adapter.ComponentModule.initModule(ComponentModule.java:433)
	at com.ibm.domino.xsp.module.nsf.NSFComponentModule.initModule(NSFComponentModule.java:427)
	at com.ibm.domino.xsp.module.nsf.NSFService.loadModule(NSFService.java:571)
	at com.ibm.domino.xsp.module.nsf.NSFService.doServiceInternal(NSFService.java:449)
	at com.ibm.domino.xsp.module.nsf.NSFService.doService(NSFService.java:352)
	at com.ibm.designer.runtime.domin
o.adapter.LCDEnvironment.doService(LCDEnvironment.java:304)
	at com.ibm.designer.runtime.domino.adapter.LCDEnvironment.service(LCDEnvironment.java:261)
	at com.ibm.domino.xsp.bridge.http.engine.XspCmdManager.service(XspCmdManager.java:291)
Caused by: com.ibm.xsp.FacesExceptionEx: java.lang.Error: Unresolved compilation problems: 
	The import com.ibm.xsp.extlib.resources cannot be resolved
	The import com.ibm.xsp.extlib.util cannot be resolved
	ExtLibResources cannot be resolved
	ExtLibResources cannot be resolved
	The method addEncodeResource(FacesContext, DojoModuleResource) is undefined for the type XBlogResources
	ExtLibUtil cannot be resolved

	at com.ibm.xsp.config.CLBootStrap.initContext(CLBootStrap.java:73)
	at com.ibm.xsp.config.BootStrap.init(BootStrap.java:60)
	at com.ibm.xsp.config.ConfigureCoreListener.contextInitialized(ConfigureCoreListener.java:58)
	at com.ib
m.designer.runtime.domino.adapter.ComponentModule.initModule(ComponentModule.java:425)
	... 7 more
Caused by: java.lang.Error: Unresolved compilation problems: 
	The import com.ibm.xsp.extlib.resources cannot be resolved
	The import com.ibm.xsp.extlib.util cannot be resolved
	ExtLibResources cannot be resolved
	ExtLibResources cannot be resolved
	The method addEncodeResource(FacesContext, DojoModuleResource) is undefined for the type XBlogResources
	ExtLibUtil cannot be resolved

	at com.xblog.renderkit.DebugComponentTreeRenderer.<init>(DebugComponentTreeRenderer.java:18)
	at java.lang.J9VMInternals.newInstanceImpl(Native Method)
	at java.lang.Class.newInstance(Class.java:1325)
	at com.sun.faces.config.ConfigureListener.configure(ConfigureListener.java:926)
	at com.sun.faces.config.ConfigureListener.configure(ConfigureListener.java:965)
	at com.sun.faces.
config.ConfigureListener.configure(ConfigureListener.java:489)
	at com.sun.faces.config.ConfigureListener.contextInitialized(ConfigureListener.java:410)
	at com.ibm.xsp.config.CLBootStrap.initContext(CLBootStrap.java:65)
	... 10 more

SEVERE
com.ibm.domino.xsp.bridge.http.engine.XspCmdManager
service
java.lang.RuntimeException: com.ibm.xsp.FacesExceptionEx: java.lang.Error: Unresolved compilation problems: 
	The import com.ibm.xsp.extlib.resources cannot be resolved
	The import com.ibm.xsp.extlib.util cannot be resolved
	ExtLibResources cannot be resolved
	ExtLibResources cannot be resolved
	The method addEncodeResource(FacesContext, DojoModuleResource) is undefined for the type XBlogResources
	ExtLibUtil cannot be resolved

	at com.ibm.designer.runtime.domino.adapter.ComponentModule.initModule(ComponentModule.java:433)
	at com.ibm.domino.xsp.module.nsf.NSFComponentModule.initModule(NSFComponentModule.java:427)
	at com.ibm.domino.xsp.module.nsf.NSFService.loadModule(NSFService.java:571)
	at com.ibm.domino.xsp.module.nsf.NSFService.doServiceInternal(NSFService.java:449)
	at com.ibm.domino.xsp.module.nsf.NSFService.doService(NSFService.java:352)
	at com.ibm.designer.runtime.domin
o.adapter.LCDEnvironment.doService(LCDEnvironment.java:304)
	at com.ibm.designer.runtime.domino.adapter.LCDEnvironment.service(LCDEnvironment.java:261)
	at com.ibm.domino.xsp.bridge.http.engine.XspCmdManager.service(XspCmdManager.java:291)
Caused by: com.ibm.xsp.FacesExceptionEx: java.lang.Error: Unresolved compilation problems: 
	The import com.ibm.xsp.extlib.resources cannot be resolved
	The import com.ibm.xsp.extlib.util cannot be resolved
	ExtLibResources cannot be resolved
	ExtLibResources cannot be resolved
	The method addEncodeResource(FacesContext, DojoModuleResource) is undefined for the type XBlogResources
	ExtLibUtil cannot be resolved

	at com.ibm.xsp.config.CLBootStrap.initContext(CLBootStrap.java:73)
	at com.ibm.xsp.config.BootStrap.init(BootStrap.java:60)
	at com.ibm.xsp.config.ConfigureCoreListener.contextInitialized(ConfigureCoreListener.java:58)
	at com.ib
m.designer.runtime.domino.adapter.ComponentModule.initModule(ComponentModule.java:425)
	... 7 more
Caused by: java.lang.Error: Unresolved compilation problems: 
	The import com.ibm.xsp.extlib.resources cannot be resolved
	The import com.ibm.xsp.extlib.util cannot be resolved
	ExtLibResources cannot be resolved
	ExtLibResources cannot be resolved
	The method addEncodeResource(FacesContext, DojoModuleResource) is undefined for the type XBlogResources
	ExtLibUtil cannot be resolved

	at com.xblog.renderkit.DebugComponentTreeRenderer.<init>(DebugComponentTreeRenderer.java:18)
	at java.lang.J9VMInternals.newInstanceImpl(Native Method)
	at java.lang.Class.newInstance(Class.java:1325)
	at com.sun.faces.config.ConfigureListener.configure(ConfigureListener.java:926)
	at com.sun.faces.config.ConfigureListener.configure(ConfigureListener.java:965)
	at com.sun.faces.
config.ConfigureListener.configure(ConfigureListener.java:489)
	at com.sun.faces.config.ConfigureListener.contextInitialized(ConfigureListener.java:410)
	at com.ibm.xsp.config.CLBootStrap.initContext(CLBootStrap.java:65)
	... 10 more

I did put the latest XPagesExtensionLibrary on the server and stopped/started HTTP for 8.5.2