Handle pdf errors when changing docs

src-ui/src/app/components/common/pdf-viewer/pdf-viewer.component.ts

@@ -465,8 +465,14 @@ export class PdfViewerComponent
 
     this.clear()
 
+    if (this.pdfViewer) {
+      this.pdfViewer._resetView()
+      this.pdfViewer = null
+    }
+
     this.setupViewer()
 
+    try {
       this.loadingTask = PDFJS.getDocument(this.getDocumentParams())
 
       this.loadingTask!.onProgress = (progressData: PDFProgressData) => {
@@ -492,6 +498,9 @@ export class PdfViewerComponent
             this.onError.emit(error)
           },
         })
+    } catch (e) {
+      this.onError.emit(e)
+    }
   }
 
   private update() {