diff --git a/source/NVDAObjects/UIA/__init__.py b/source/NVDAObjects/UIA/__init__.py
index 4c57ae22374..68a12dd7000 100644
--- a/source/NVDAObjects/UIA/__init__.py
+++ b/source/NVDAObjects/UIA/__init__.py
@@ -122,13 +122,15 @@ def _getControlFieldForObject(self, obj):
 	def _iterUIARangeByUnit(self,rangeObj,unit):
 		tempRange=rangeObj.clone()
 		tempRange.MoveEndpointByRange(UIAHandler.TextPatternRangeEndpoint_End,rangeObj,UIAHandler.TextPatternRangeEndpoint_Start)
-		while tempRange.MoveEndpointByUnit(UIAHandler.TextPatternRangeEndpoint_End,unit,1)>0:
+		endRange=tempRange.Clone()
+		while endRange.Move(unit,1)>0:
+			tempRange.MoveEndpointByRange(UIAHandler.TextPatternRangeEndpoint_End,endRange,UIAHandler.TextPatternRangeEndpoint_Start)
 			pastEnd=tempRange.CompareEndpoints(UIAHandler.TextPatternRangeEndpoint_End,rangeObj,UIAHandler.TextPatternRangeEndpoint_End)>0
 			if pastEnd:
 				tempRange.MoveEndpointByRange(UIAHandler.TextPatternRangeEndpoint_End,rangeObj,UIAHandler.TextPatternRangeEndpoint_End)
 			yield tempRange.clone()
 			if pastEnd:
-				break
+				return
 			tempRange.MoveEndpointByRange(UIAHandler.TextPatternRangeEndpoint_Start,tempRange,UIAHandler.TextPatternRangeEndpoint_End)
 		# Ensure that we always reach the end of the outer range, even if the units seem to stop somewhere inside
 		if tempRange.CompareEndpoints(UIAHandler.TextPatternRangeEndpoint_End,rangeObj,UIAHandler.TextPatternRangeEndpoint_End)<0:
@@ -149,6 +151,8 @@ def _getFormatFieldsAndText(self,tempRange,formatConfig):
 			elif annotationTypes==UIAHandler.handler.ReservedMixedAttributeValue:
 				for r in self._iterUIARangeByUnit(tempRange,UIAHandler.TextUnit_Word):
 					text=r.GetText(-1)
+					if not text:
+						continue
 					r.MoveEndpointByRange(UIAHandler.TextPatternRangeEndpoint_End,r,UIAHandler.TextPatternRangeEndpoint_Start)
 					r.ExpandToEnclosingUnit(UIAHandler.TextUnit_Character)
 					try:
diff --git a/source/appModules/powerpnt.py b/source/appModules/powerpnt.py
index 182a4fa2f60..317ce2d74f9 100644
--- a/source/appModules/powerpnt.py
+++ b/source/appModules/powerpnt.py
@@ -1039,6 +1039,9 @@ def script_slideChange(self,gesture):
 		gesture.send()
 		self.rootNVDAObject.handleSlideChange()
 
+class ReviewableSlideshowTreeInterceptor(ReviewCursorManager,SlideShowTreeInterceptor):
+	"""A TreeInterceptor for Slide show content but with caret navigation via ReviewCursorManager."""
+
 	__gestures={
 		"kb:space":"slideChange",
 		"kb:enter":"slideChange",
@@ -1048,10 +1051,6 @@ def script_slideChange(self,gesture):
 		"kb:control+shift+s":"toggleNotesMode",
 	}
 
-class ReviewableSlideshowTreeInterceptor(ReviewCursorManager,SlideShowTreeInterceptor):
-	"""A TreeInterceptor for Slide show content but with caret navigation via ReivewCursorManager."""
-	pass
-
 class SlideShowWindow(PaneClassDC):
 
 	_lastSlideChangeID=None
diff --git a/user_docs/en/changes.t2t b/user_docs/en/changes.t2t
index 3b014db10bc..b97d57b6e0f 100644
--- a/user_docs/en/changes.t2t
+++ b/user_docs/en/changes.t2t
@@ -21,9 +21,10 @@
 == Bug Fixes ==
 - Character descriptions are now handled correctly for conjunct characters in certain Indian languages. (#4582)
 - If the "Trust voice's language when processing characters and symbols" option is enabled, the Punctuation/Symbol pronunciation dialog now correctly uses the voice language. Also, the language for which pronunciation is being edited is shown in the dialog's title. (#4930)
--In Internet Explorer and other MSHTML controls, typed characters are no longer inappropriately announced in editable combo boxes such as the Google search field on the Google home page. (#4976)
+- In Internet Explorer and other MSHTML controls, typed characters are no longer inappropriately announced in editable combo boxes such as the Google search field on the Google home page. (#4976)
 - When selecting colors in Microsoft Office applications, color names are now reported. (#3045)
 - Danish braille output now works again. (#4986)
+- pageUp / pageDown can now be used again to change slides within a PowerPoint slide show. (#4850)
 
 
 == Changes for Developers ==