# Playground misbehaving (Chapter 3) **URL:** \ **Category:** Realm: Building Modern Swift Apps with Realm\ **Created:** [April 17, 2018, 6:58pm UTC](https://forums.kodeco.com/t/playground-misbehaving-chapter-3/41690 "2018-04-17T18:58:30Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![rustprooffish](https://assets.chunter.kodeco.com/user_avatar/forums.kodeco.com/rustprooffish/32/102075_2.png) [@rustprooffish](https://forums.kodeco.com/u/rustprooffish)\ **Post date:** [April 17, 2018, 6:58pm UTC](https://forums.kodeco.com/t/playground-misbehaving-chapter-3/41690/1 "2018-04-17T18:58:33Z")
I’m trying to work through the examples in this chapter but the playground is somewhat erratic in its behaviour. Sometimes a typo or partially completed line of code triggers an error message in the editor and then the playground hangs - the only way to get up and running again is to quit Xcode and run ./boostrap.sh (although it sometimes takes one or two attempts to clear any errors relating to missing source files). Any pointers gratefully received! ---
**Author:** ![gilroykilroy](https://assets.chunter.kodeco.com/user_avatar/forums.kodeco.com/gilroykilroy/32/100770_2.png) [@gilroykilroy](https://forums.kodeco.com/u/gilroykilroy)\ **Post date:** [April 17, 2018, 7:22pm UTC](https://forums.kodeco.com/t/playground-misbehaving-chapter-3/41690/2 "2018-04-17T19:22:57Z")
You seem to be getting further than I am. As soon as I run the playground I get a bunch of “error: Couldn’t lookup symbols:” messages. ---
**Author:** ![rustprooffish](https://assets.chunter.kodeco.com/user_avatar/forums.kodeco.com/rustprooffish/32/102075_2.png) [@rustprooffish](https://forums.kodeco.com/u/rustprooffish)\ **Post date:** [April 17, 2018, 7:24pm UTC](https://forums.kodeco.com/t/playground-misbehaving-chapter-3/41690/3 "2018-04-17T19:24:38Z")
I’ve got a feeling it’s related to introspection / reflection which Swift isn’t overly good at (I found Java a lot more reliable). I’m still a relatively inexperienced iOS developer and the stack trace is even more incomprehensible than normal! ---
**Author:** ![dozeydave](https://s3.amazonaws.com/cdn.raywenderlich.com/community/forum-assets/noun-game-ghost-878668.png) [@dozeydave](https://forums.kodeco.com/u/dozeydave)\ **Post date:** [April 21, 2018, 9:49am UTC](https://forums.kodeco.com/t/playground-misbehaving-chapter-3/41690/4 "2018-04-21T09:49:05Z")
@gilroykilroy i seem to be having the same problem as you. Have you found a solution? ---
**Author:** ![gilroykilroy](https://assets.chunter.kodeco.com/user_avatar/forums.kodeco.com/gilroykilroy/32/100770_2.png) [@gilroykilroy](https://forums.kodeco.com/u/gilroykilroy)\ **Post date:** [April 21, 2018, 4:56pm UTC](https://forums.kodeco.com/t/playground-misbehaving-chapter-3/41690/5 "2018-04-21T16:56:26Z")
No solution. I think Apple needs to do a better job of supporting playgrounds that use third party frameworks. ---
**Author:** ![rustprooffish](https://assets.chunter.kodeco.com/user_avatar/forums.kodeco.com/rustprooffish/32/102075_2.png) [@rustprooffish](https://forums.kodeco.com/u/rustprooffish)\ **Post date:** [April 22, 2018, 6:30pm UTC](https://forums.kodeco.com/t/playground-misbehaving-chapter-3/41690/6 "2018-04-22T18:30:58Z")
Not all of the Playgrounds misbehave if that makes you feel any better. I’ve now completed the book and generally most of them work pretty well with the odd glitch resolved by running the bootstrap command again after closing Xcode. ---
**Author:** ![gewill](https://assets.chunter.kodeco.com/user_avatar/forums.kodeco.com/gewill/32/109180_2.png) [@gewill](https://forums.kodeco.com/u/gewill)\ **Post date:** [April 24, 2018, 8:41am UTC](https://forums.kodeco.com/t/playground-misbehaving-chapter-3/41690/7 "2018-04-24T08:41:07Z")
Same to me. My solution is `git clone https://github.com/realm/realm-cocoa.git`, drop playground( in the book) into RealmExamples.xcworkspace. To get this Playground running do the following: 1. In the scheme selector choose RealmSwift \> iPhone 6s 2. Press Cmd + B 3. If the Playground didn’t already run press the ▶︎ button at the bottom ---
**Author:** ![dankorkelia](https://assets.chunter.kodeco.com/user_avatar/forums.kodeco.com/dankorkelia/32/81494_2.png) [@dankorkelia](https://forums.kodeco.com/u/dankorkelia)\ **Post date:** [April 30, 2018, 2:03pm UTC](https://forums.kodeco.com/t/playground-misbehaving-chapter-3/41690/8 "2018-04-30T14:03:57Z")
This seems to be an issue with Xcode 9.3 and playground. A lot of people reporting crashes. Although you didn’t say which Xcode you are running so maybe not related. ---
**Author:** ![rustprooffish](https://assets.chunter.kodeco.com/user_avatar/forums.kodeco.com/rustprooffish/32/102075_2.png) [@rustprooffish](https://forums.kodeco.com/u/rustprooffish)\ **Post date:** [May 1, 2018, 7:43am UTC](https://forums.kodeco.com/t/playground-misbehaving-chapter-3/41690/9 "2018-05-01T07:43:50Z")
Sorry - should have said. It is Xcode 9.3. Hopefully it will be rectified in the next point release ---
**Author:** ![icanzilb](https://assets.chunter.kodeco.com/user_avatar/forums.kodeco.com/icanzilb/32/109333_2.png) [@icanzilb](https://forums.kodeco.com/u/icanzilb)\ **Post date:** [May 1, 2018, 9:00am UTC](https://forums.kodeco.com/t/playground-misbehaving-chapter-3/41690/10 "2018-05-01T09:00:36Z")
yeah, it really is an issue with Xcode 9.3/CP - we’re working on the solution right now 👍🏼 ---
**Author:** ![freak4pc](https://assets.chunter.kodeco.com/user_avatar/forums.kodeco.com/freak4pc/32/101113_2.png) [@freak4pc](https://forums.kodeco.com/u/freak4pc)\ **Post date:** [May 5, 2018, 1:52pm UTC](https://forums.kodeco.com/t/playground-misbehaving-chapter-3/41690/11 "2018-05-05T13:52:42Z")
Heya ! Please look at the solutions outlined in the other thread: > [@Realm - Building Modern Swift Apps : Script Error](https://forums.kodeco.com/t/realm-building-modern-swift-apps-script-error/41747/32): > > Another update on this: We’ll be releasing relatively soon an updated Playgrounds edition that doesn’t rely on CocoaPods at all. For the time being, with the existing version there are two workarounds : Use CocoaPods 1.4 instead of 1.5 If you must use 1.5, you can add the following at the end of your Podfile: # Workaround for Cocoapods issue #7689 post\_install do |installer| installer.pods\_project.build\_configurations.each do |config| config.build\_settings.delete('CODE\_SIGNING\_AL… Regardless, we’ll be releasing a new version which fixes this soon!