Binary XML file line #6: Binary XML file line #6: Error inflating class ImageView

[luc-vocab]

I saw the following crashreport on crashlytics from a user of my app (https://github.com/lucwastiaux/AnkiReview). It seems to be a rare bug, probably related to a particular version of android. Thank for any suggestions you may have. it doesn't seem to occur frequently at all.

Here's the crashlytics information I have:
Device
Brand: HUAWEI
Model: EML-AL00
Orientation: Portrait
RAM free: 1.22 GB
Disk free: 11.07 GB
Operating System
Version: 9
Orientation: Portrait
Rooted: No

Fatal Exception: android.view.InflateException: Binary XML file line #6: Binary XML file line #6: Error inflating class ImageView

Caused by android.content.res.Resources$NotFoundException: Drawable (missing name) with resource ID #0x7f08008e

Caused by android.content.res.Resources$NotFoundException: Unable to find resource ID #0x7f08008e
at android.content.res.ResourcesImpl.getResourcePackageName(ResourcesImpl.java:339)
at android.content.res.HwResourcesImpl.loadDrawable(HwResourcesImpl.java:894)
at android.content.res.ResourcesImpl.loadDrawable(ResourcesImpl.java:874)
at android.content.res.Resources.loadDrawable(Resources.java:1076)
at android.content.res.TypedArray.getDrawableForDensity(TypedArray.java:1009)
at android.content.res.TypedArray.getDrawable(TypedArray.java:984)
at android.widget.ImageView.(ImageView.java:210)
at android.widget.ImageView.(ImageView.java:193)
at android.support.v7.widget.AppCompatImageView.(AppCompatImageView.java:72)
at android.support.v7.widget.AppCompatImageView.(AppCompatImageView.java:68)
at android.support.v7.app.AppCompatViewInflater.createImageView(AppCompatViewInflater.java:182)
at android.support.v7.app.AppCompatViewInflater.createView(AppCompatViewInflater.java:106)
at android.support.v7.app.AppCompatDelegateImpl.createView(AppCompatDelegateImpl.java:1266)
at android.support.v7.app.AppCompatDelegateImpl.onCreateView(AppCompatDelegateImpl.java:1316)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:783)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:741)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:874)
at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
at com.thebluealliance.spectrum.internal.ColorItem.init(ColorItem.java:74)
at com.thebluealliance.spectrum.internal.ColorItem.(ColorItem.java:45)
at com.thebluealliance.spectrum.SpectrumPalette.createColorItem(SpectrumPalette.java:275)
at com.thebluealliance.spectrum.SpectrumPalette.createPaletteView(SpectrumPalette.java:244)
at com.thebluealliance.spectrum.SpectrumPalette.setColors(SpectrumPalette.java:101)
at com.thebluealliance.spectrum.SpectrumDialog.onCreateDialog(SpectrumDialog.java:372)
at android.support.v4.app.DialogFragment.onGetLayoutInflater(DialogFragment.java:330)
at android.support.v4.app.Fragment.performGetLayoutInflater(Fragment.java:1308)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1460)
at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1784)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1852)
at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:802)
at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2625)
at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2411)
at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2366)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2273)
at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:733)
at android.os.Handler.handleCallback(Handler.java:891)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:207)
at android.app.ActivityThread.main(ActivityThread.java:7470)
at java.lang.reflect.Method.invoke(Method.java)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:524)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:958)