# Error: Undefined Symbol: \_RegisterSuspendCallback when building for iOS

**URL:** <https://qa.fmod.com/t/error-undefined-symbol-registersuspendcallback-when-building-for-ios/18050>\
**Category:** Unity\
**Tags:** ios, unity\
**Created:** [December 5, 2021, 5:16pm UTC](https://qa.fmod.com/t/error-undefined-symbol-registersuspendcallback-when-building-for-ios/18050 "2021-12-05T17:16:35Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![ayrton2388](https://avatars.discourse-cdn.com/v4/letter/a/2acd7d/32.png) [@ayrton2388](https://qa.fmod.com/u/ayrton2388)\
**Post date:** [December 5, 2021, 5:16pm UTC](https://qa.fmod.com/t/error-undefined-symbol-registersuspendcallback-when-building-for-ios/18050/1 "2021-12-05T17:16:35Z")

</div>

Hello,  
I’m having an issue when trying to build a project on my iPad. I am getting an error because of fmod, looking like this:

> Ld /Users/simsoft/Library/Developer/Xcode/DerivedData/Unity-iPhone-gslywripzwdgevchzhzoizgffwrd/Build/Products/ReleaseForRunning-iphoneos/UnityFramework.framework/UnityFramework normal (in target ‘UnityFramework’ from project ‘Unity-iPad’)  
> cd /Users/simsoft/Documents/GitHub/builds/VCS  
> /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -target arm64-apple-ios12.0 -dynamiclib -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS15.0.sdk -L/Users/simsoft/Library/Developer/Xcode/DerivedData/Unity-iPhone-gslywripzwdgevchzhzoizgffwrd/Build/Products/ReleaseForRunning-iphoneos -L/Users/simsoft/Documents/GitHub/builds/VCS/Libraries -L/Users/simsoft/Documents/GitHub/builds/VCS/Libraries/Vendor/Paroxe/PDFRenderer/Plugins/iOS -L/Users/simsoft/Documents/GitHub/builds/VCS/Libraries/Plugins/FMOD/lib/ios -L/Users/simsoft/Documents/GitHub/builds/VCS/Libraries/Plugins/iOS -F/Users/simsoft/Library/Developer/Xcode/DerivedData/Unity-iPhone-gslywripzwdgevchzhzoizgffwrd/Build/Products/ReleaseForRunning-iphoneos -filelist /Users/simsoft/Library/Developer/Xcode/DerivedData/Unity-iPhone-gslywripzwdgevchzhzoizgffwrd/Build/Intermediates.noindex/Unity-iPad.build/ReleaseForRunning-iphoneos/UnityFramework.build/Objects-normal/arm64/UnityFramework.LinkFileList -install\_name [@]rpath/UnityFramework.framework/UnityFramework -Xlinker -rpath -Xlinker [@]executable\_path/Frameworks -Xlinker -rpath -Xlinker [@]loader\_path/Frameworks -Xlinker -map -Xlinker /Users/simsoft/Library/Developer/Xcode/DerivedData/Unity-iPhone-gslywripzwdgevchzhzoizgffwrd/Build/Intermediates.noindex/Unity-iPad.build/ReleaseForRunning-iphoneos/UnityFramework.build/UnityFramework-LinkMap-normal-arm64.txt -dead\_strip -Xlinker -object\_path\_lto -Xlinker /Users/simsoft/Library/Developer/Xcode/DerivedData/Unity-iPhone-gslywripzwdgevchzhzoizgffwrd/Build/Intermediates.noindex/Unity-iPad.build/ReleaseForRunning-iphoneos/UnityFramework.build/Objects-normal/arm64/UnityFramework\_lto.o -fembed-bitcode-marker -stdlib=libc++ -fobjc-arc -fobjc-link-runtime -weak\_framework CoreMotion -weak-lSystem -liPhone-lib -framework Security -framework MediaToolbox -framework CoreText -framework AudioToolbox -weak\_framework AVFoundation -framework AVKit -framework CFNetwork -framework CoreGraphics -framework CoreMedia -weak\_framework CoreMotion -framework CoreVideo -framework Foundation -framework OpenAL -framework OpenGLES -framework QuartzCore -framework SystemConfiguration -framework UIKit -liconv.2 -lil2cpp /Users/simsoft/Documents/GitHub/builds/VCS/Libraries/Vendor/Paroxe/PDFRenderer/Plugins/iOS/pdfrenderer.a -lfmodstudiounityplugin -lresonanceaudio -lopus\_egpv -framework CoreLocation -weak\_framework Metal -weak\_framework GameController -Xlinker -dependency\_info -Xlinker /Users/simsoft/Library/Developer/Xcode/DerivedData/Unity-iPhone-gslywripzwdgevchzhzoizgffwrd/Build/Intermediates.noindex/Unity-iPad.build/ReleaseForRunning-iphoneos/UnityFramework.build/Objects-normal/arm64/UnityFramework\_dependency\_info.dat -o /Users/simsoft/Library/Developer/Xcode/DerivedData/Unity-iPhone-gslywripzwdgevchzhzoizgffwrd/Build/Products/ReleaseForRunning-iphoneos/UnityFramework.framework/UnityFramework
> 
> Undefined symbols for architecture arm64:  
> “\_RegisterSuspendCallback”, referenced from:  
> \_RuntimeManager\_Initialize\_mBEBF28EF713CC3E1FEEFC3D62CFAF3C678CCC73F in AtmisaioPlugins3.o \_RuntimeManager\_RegisterSuspendCallback\_mA88CFC22DF4FF3E80673990BE5E0EE9A8C1F4CF7 in AtmisaioPlugins3.o  
> (maybe you meant: \_RuntimeManager\_RegisterSuspendCallback\_mA88CFC22DF4FF3E80673990BE5E0EE9A8C1F4CF7)  
> ld: symbol(s) not found for architecture arm64  
> clang: error: linker command failed with exit code 1 (use -v to see invocation)

I am using Unity 2019.4.4f1, xcode 13.1, MacOS 12.0.1 (monterey), and fmod 2.00.07. Any ideas why this is happening, or how can we fix it? I’d appreciate any kind of help, i really have no idea how to fix this and get the build working…

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<div class="post-metadata">

**Author:** ![jeff\_fmod](https://yyz2.discourse-cdn.com/flex036/user_avatar/qa.fmod.com/jeff_fmod/32/1766_2.png) [@jeff\_fmod](https://qa.fmod.com/u/jeff_fmod)\
**Post date:** [December 13, 2021, 2:10am UTC](https://qa.fmod.com/t/error-undefined-symbol-registersuspendcallback-when-building-for-ios/18050/2 "2021-12-13T02:10:03Z")

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Sounds like the same issue as described [here](https://qa.fmod.com/t/link-issue-in-ios/17941), except I’m guessing you haven’t modified your XCode project at all?  
I have not been able to reproduce this error with your version, can you tell me a little more about your project? Are you using custom plugins, or anything like that?