Don't try to parse JSON being returned from the API

app/Http/Controllers/Api/Client/Servers/FileController.php

@@ -85,7 +85,9 @@ class FileController extends ClientApiController
         return Response::create(
             $this->fileRepository->setServer($server)->getContent(
                 $request->get('file'), config('pterodactyl.files.max_edit_size')
-            )
+            ),
+            Response::HTTP_OK,
+            ['Content-Type' => 'text/plain']
         );
     }
 

resources/scripts/api/server/files/getFileContents.ts

@@ -2,7 +2,11 @@ import http from '@/api/http';
 
 export default (server: string, file: string): Promise<string> => {
     return new Promise((resolve, reject) => {
-        http.get(`/api/client/servers/${server}/files/contents`, { params: { file } })
+        http.get(`/api/client/servers/${server}/files/contents`, {
+            params: { file },
+            transformResponse: res => res,
+            responseType: 'text/plain',
+        })
             .then(({ data }) => resolve(data))
             .catch(reject);
     });