# Syncano Backend not working on iOS preview **URL:** \ **Category:** General\ **Created:** [July 19, 2016, 9:43pm UTC](https://forums.fusetools.com/t/syncano-backend-not-working-on-ios-preview/6573 "2016-07-19T21:43:47Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![asaxionis](https://avatars.discourse-cdn.com/v4/letter/a/4491bb/32.png) [@asaxionis](https://forums.fusetools.com/u/asaxionis)\ **Post date:** [July 19, 2016, 9:43pm UTC](https://forums.fusetools.com/t/syncano-backend-not-working-on-ios-preview/6573/1 "2016-07-19T21:43:47Z")
Has anyone tried @bolav 's new Syncano backend, I have run into a weird error when running it on my iOS device, it works on the desktop but for some reason i get errors when it occurs in the preview for iOS i haven’t tested it on android but i would assume the same… here what it is printing on the iOS device when i run it. ```auto JavaScript error in syncano-js-1.0.22/dist/syncano.fuse.js line 34806. Unexpected keyword 'const'. Const declarations are not supported in strict mode. ``` and then it also gives me this other error ```auto JavaScript error in MainView.ux line 10. Syncano is not a function. (In Syncano, Syncano is an instance of Object) ``` this is based off of: [https://github.com/bolav/fuse-example-using-syncano](https://github.com/bolav/fuse-example-using-syncano) It works in desktop preview but that’s it, which is weird. ---
**Author:** ![Vegard\_Strand\_Lende](https://yyz1.discourse-cdn.com/flex035/user_avatar/forums.fusetools.com/vegard_strand_lende/32/349_2.png) [@Vegard\_Strand\_Lende](https://forums.fusetools.com/u/Vegard_Strand_Lende)\ **Post date:** [July 20, 2016, 10:27am UTC](https://forums.fusetools.com/t/syncano-backend-not-working-on-ios-preview/6573/2 "2016-07-20T10:27:28Z")
`const` is a keyword in ES6. I believe that iOS is running ES5, you probably need to use babel to transpile your code to ES5. ---
**Author:** ![asaxionis](https://avatars.discourse-cdn.com/v4/letter/a/4491bb/32.png) [@asaxionis](https://forums.fusetools.com/u/asaxionis)\ **Post date:** [July 21, 2016, 5:13am UTC](https://forums.fusetools.com/t/syncano-backend-not-working-on-ios-preview/6573/3 "2016-07-21T05:13:15Z")
Any idea how I would go about that? I’m really new to backend material if you could link me to some place I’d greatly appreciate it ---
**Author:** ![Vegard\_Strand\_Lende](https://yyz1.discourse-cdn.com/flex035/user_avatar/forums.fusetools.com/vegard_strand_lende/32/349_2.png) [@Vegard\_Strand\_Lende](https://forums.fusetools.com/u/Vegard_Strand_Lende)\ **Post date:** [July 21, 2016, 8:00am UTC](https://forums.fusetools.com/t/syncano-backend-not-working-on-ios-preview/6573/4 "2016-07-21T08:00:57Z")
Have a look at [https://babeljs.io/](https://babeljs.io/), looking at bolavs example I would just add the call to babel in the download script for syncano, then `require` the output from babel in fuse ---
**Author:** ![asaxionis](https://avatars.discourse-cdn.com/v4/letter/a/4491bb/32.png) [@asaxionis](https://forums.fusetools.com/u/asaxionis)\ **Post date:** [July 24, 2016, 9:30am UTC](https://forums.fusetools.com/t/syncano-backend-not-working-on-ios-preview/6573/5 "2016-07-24T09:30:22Z")
Hi thanks for the response and sorry about the delay! I seem to be having trouble doing this, I had manually placed the syncano in the folder from downloading it from github; so any idea how I can do that for babble I can’t seem to figure it out ---
**Author:** ![Vegard\_Strand\_Lende](https://yyz1.discourse-cdn.com/flex035/user_avatar/forums.fusetools.com/vegard_strand_lende/32/349_2.png) [@Vegard\_Strand\_Lende](https://forums.fusetools.com/u/Vegard_Strand_Lende)\ **Post date:** [July 25, 2016, 3:08pm UTC](https://forums.fusetools.com/t/syncano-backend-not-working-on-ios-preview/6573/6 "2016-07-25T15:08:04Z")
Please have a look at the babel docs or some example on stackoverflow. I think something like this should do the trick: `babel ./syncano-js-1.0.22/dist/syncano.fuse.js --out-file ./generated/syncano.js`. And then just `require(...)` the generated file in Fuse