added try/except to wipe collaboration cache tool to handle case when…

… there is no cache folder in a version of revit

extensions/pyRevitTools.extension/pyRevit.tab/Project.panel/Wipe.pulldown/Wipe Collab Cache.pushbutton/script.py

@@ -24,23 +24,26 @@ def name(self):
             ' [ Linked ]' if self.linked else ''
             )
 
-
-cmodels = []
-# grab collab caches
-for cc in bim360.get_collab_caches():
-    # add models
-    cmodels.extend(
-        [CacheModelItem(x) for x in cc.cache_models]
-        )
-    # and linked models
-    cmodels.extend(
-        [CacheModelItem(x, linked=True) for x in cc.cache_linked_models]
-        )
-
-# ask user for which model to delete
-selected_cmodels = forms.SelectFromList.show(cmodels, multiselect=True)
-if selected_cmodels:
-    # delete each selected cache
-    for cm in selected_cmodels:
-        logger.info('Deleting %s', cm)
-        bim360.clear_model_cache(cm)
+try:
+    cmodels = []
+    # grab collab caches
+    for cc in bim360.get_collab_caches():
+        # add models
+        cmodels.extend(
+            [CacheModelItem(x) for x in cc.cache_models]
+            )
+        # and linked models
+        cmodels.extend(
+            [CacheModelItem(x, linked=True) for x in cc.cache_linked_models]
+            )
+
+    # ask user for which model to delete
+    selected_cmodels = forms.SelectFromList.show(cmodels, multiselect=True)
+    if selected_cmodels:
+        # delete each selected cache
+        for cm in selected_cmodels:
+            logger.info('Deleting %s', cm)
+            bim360.clear_model_cache(cm)
+
+except:
+    nomodels = forms.alert('No Collaboration Cache for this version of Revit', title='pyRevit - Wipe Collaboration Cache', ok=True, cancel=False)