diff --git a/app/client/components/Layout.js b/app/client/components/Layout.js
index 1814d82a..312da743 100644
--- a/app/client/components/Layout.js
+++ b/app/client/components/Layout.js
@@ -439,6 +439,9 @@ Layout.prototype.buildLayout = function(boxSpec, needDynamic) {
 
 Layout.prototype._getBoxSpec = function(layoutBox) {
   var spec = {};
+  if (layoutBox.isDisposed()) {
+    return spec;
+  }
   if (layoutBox.flexSize() && layoutBox.flexSize() !== 100) {
     spec.size = layoutBox.flexSize();
   }
diff --git a/app/client/components/LinkingState.ts b/app/client/components/LinkingState.ts
index e6f3b8ac..05b4068c 100644
--- a/app/client/components/LinkingState.ts
+++ b/app/client/components/LinkingState.ts
@@ -138,6 +138,10 @@ export class LinkingState extends Disposable {
   ): ko.Computed<FilterColValues> {
     return this.autoDispose(ko.computed(() => {
       const srcRowId = this._srcSection.activeRowId();
+      if (srcRowId === null) {
+        console.warn("_simpleFilter activeRowId is null");
+        return { filters: {}, operations: {}};
+      }
       const values = valuesFunc(srcRowId);
       return {filters: {[colId]: values}, operations: {[colId]: operation}} as FilterColValues;
     }));
diff --git a/app/client/models/entities/ViewSectionRec.ts b/app/client/models/entities/ViewSectionRec.ts
index 702e0f40..9bcc7d56 100644
--- a/app/client/models/entities/ViewSectionRec.ts
+++ b/app/client/models/entities/ViewSectionRec.ts
@@ -410,7 +410,7 @@ export function createViewSectionRec(this: ViewSectionRec, docModel: DocModel):
   this.linkSrcCol = refRecord(docModel.columns, this.activeLinkSrcColRef);
   this.linkTargetCol = refRecord(docModel.columns, this.activeLinkTargetColRef);
 
-  this.activeRowId = ko.observable();
+  this.activeRowId = ko.observable(null);
 
   // If the view instance for this section is instantiated, it will be accessible here.
   this.viewInstance = ko.observable(null);