diff --git a/ui-ngx/src/app/core/utils.ts b/ui-ngx/src/app/core/utils.ts
index 7f13f08ba6..466652040f 100644
--- a/ui-ngx/src/app/core/utils.ts
+++ b/ui-ngx/src/app/core/utils.ts
@@ -226,8 +226,20 @@ export function objToBase64(obj: any): string {
     }));
 }
 
+const textDecoderUtf8 = new TextDecoder('utf-8', { fatal: true });
+const textDecoderLatin1 = new TextDecoder('iso-8859-1');
+
 export function base64toString(b64Encoded: string): string {
-  return decodeURIComponent(atob(b64Encoded).split('').map((c) => '%' + ('00' + c.charCodeAt(0).toString(16)).slice(-2)).join(''));
+  const binary = atob(b64Encoded);
+  const bytes = new Uint8Array(binary.length);
+  for (let i = 0; i < binary.length; i++) {
+    bytes[i] = binary.charCodeAt(i);
+  }
+  try {
+    return textDecoderUtf8.decode(bytes);
+  } catch {
+    return textDecoderLatin1.decode(bytes);
+  }
 }
 
 export function objToBase64URI(obj: any): string {
@@ -235,8 +247,7 @@ export function objToBase64URI(obj: any): string {
 }
 
 export function base64toObj(b64Encoded: string): any {
-  const json = decodeURIComponent(atob(b64Encoded).split('').map((c) => '%' + ('00' + c.charCodeAt(0).toString(16)).slice(-2)).join(''));
-  return JSON.parse(json);
+  return JSON.parse(base64toString(b64Encoded));
 }
 
 export function stringToBase64(value: string): string {
diff --git a/ui-ngx/src/app/shared/components/file-input.component.ts b/ui-ngx/src/app/shared/components/file-input.component.ts
index 727b1628dc..5b09c30c25 100644
--- a/ui-ngx/src/app/shared/components/file-input.component.ts
+++ b/ui-ngx/src/app/shared/components/file-input.component.ts
@@ -239,7 +239,18 @@ export class FileInputComponent extends PageComponent implements AfterViewInit,
       if (this.readAsBinary) {
         reader.readAsBinaryString(file.file);
       } else {
-        reader.readAsText(file.file);
+        file.file.arrayBuffer().then(buf => {
+          const bytes = new Uint8Array(buf);
+          let text: string;
+          try {
+            text = new TextDecoder('utf-8', {fatal: true}).decode(bytes);
+          } catch {
+            text = new TextDecoder('iso-8859-1').decode(bytes);
+          }
+           Object.defineProperty(reader, 'readyState', {value: FileReader.DONE, configurable: true});
+          Object.defineProperty(reader, 'result',    {value: text,            configurable: true});
+          reader.onload(new ProgressEvent('load') as ProgressEvent<FileReader>);
+        }).catch(() => reader.onerror(new ProgressEvent('error') as ProgressEvent<FileReader>));
       }
     });
   }