title: AAPT: Error: Resource attr/(various) not found
body: <p>Having all kinds of problems tonight. Downloaded updated Android Studio and Gradle and coded a little and then started getting these errors. Have tried uninstalling android studio, changing the version of Gradle in my build file to an earlier version, using an older version of android studio, deleting the Gradle cache, and maybe one or three other things. Older versions of Android Studio now say my project must be used with Android 3.6.</p>
  <p>These things the build output is complaining about all seem to exist in the file it's talking about at the exact line. Tried commenting them out... that didn't work either.</p>
  <p>Little out of my league here. Any of you gray hairs see something I'm missing?</p>
  <p>Any help much appreciated.</p>
  <p>===========================================================================</p>
  <blockquote>
  <p>C:\Users\me\.gradle\caches\transforms-2\files-2.1\d083c96bf16f0afa497f0903aac86f7e\constraintlayout-2.0.0-beta2\res\values\values.xml:268:5-4347:
  AAPT: error: resource attr/flow_horizontalSeparator (aka
  com.myproject.myproject:attr/flow_horizontalSeparator) not found.
  C:\Users\me\.gradle\caches\transforms-2\files-2.1\d083c96bf16f0afa497f0903aac86f7e\constraintlayout-2.0.0-beta2\res\values\values.xml:268:5-4347:
  AAPT: error: resource attr/flow_verticalSeparator (aka
  com.myproject.myproject:attr/flow_verticalSeparator) not found.
  C:\Users\me\.gradle\caches\transforms-2\files-2.1\d083c96bf16f0afa497f0903aac86f7e\constraintlayout-2.0.0-beta2\res\values\values.xml:269:5-3548:
  AAPT: error: resource attr/flow_horizontalSeparator (aka
  com.myproject.myproject:attr/flow_horizontalSeparator) not found.
  C:\Users\me\.gradle\caches\transforms-2\files-2.1\d083c96bf16f0afa497f0903aac86f7e\constraintlayout-2.0.0-beta2\res\values\values.xml:269:5-3548:
  AAPT: error: resource attr/flow_verticalSeparator (aka
  com.myproject.myproject:attr/flow_verticalSeparator) not found.
  C:\Users\me\.gradle\caches\transforms-2\files-2.1\d083c96bf16f0afa497f0903aac86f7e\constraintlayout-2.0.0-beta2\res\values\values.xml:271:5-4382:
  AAPT: error: resource attr/flow_horizontalSeparator (aka
  com.myproject.myproject:attr/flow_horizontalSeparator) not found.
  C:\Users\me\.gradle\caches\transforms-2\files-2.1\d083c96bf16f0afa497f0903aac86f7e\constraintlayout-2.0.0-beta2\res\values\values.xml:271:5-4382:
  AAPT: error: resource attr/flow_verticalSeparator (aka
  com.myproject.myproject:attr/flow_verticalSeparator) not found.
  C:\Users\me\.gradle\caches\transforms-2\files-2.1\d083c96bf16f0afa497f0903aac86f7e\constraintlayout-2.0.0-beta2\res\values\values.xml:271:5-4382:
  AAPT: error: resource attr/motionProgress (aka
  com.myproject.myproject:attr/motionProgress) not found.
  C:\Users\me\.gradle\caches\transforms-2\files-2.1\d083c96bf16f0afa497f0903aac86f7e\constraintlayout-2.0.0-beta2\res\values\values.xml:274:5-588:
  AAPT: error: resource attr/motionProgress (aka
  com.myproject.myproject:attr/motionProgress) not found.
  C:\Users\me\.gradle\caches\transforms-2\files-2.1\d083c96bf16f0afa497f0903aac86f7e\constraintlayout-2.0.0-beta2\res\values\values.xml:275:5-652:
  AAPT: error: resource attr/motionProgress (aka
  com.myproject.myproject:attr/motionProgress) not found.
  C:\Users\me\.gradle\caches\transforms-2\files-2.1\d083c96bf16f0afa497f0903aac86f7e\constraintlayout-2.0.0-beta2\res\values\values.xml:284:5-653:
  AAPT: error: resource attr/motionProgress (aka
  com.myproject.myproject:attr/motionProgress) not found.
  C:\Users\me\.gradle\caches\transforms-2\files-2.1\d083c96bf16f0afa497f0903aac86f7e\constraintlayout-2.0.0-beta2\res\values\values.xml:284:5-653:
  AAPT: error: resource attr/waveDecay (aka
  com.myproject.myproject:attr/waveDecay) not found.
  C:\Users\me\.gradle\caches\transforms-2\files-2.1\d083c96bf16f0afa497f0903aac86f7e\constraintlayout-2.0.0-beta2\res\values\values.xml:288:5-232:
  AAPT: error: resource attr/motionPathRotate (aka
  com.myproject.myproject:attr/motionPathRotate) not found.
  C:\Users\me\.gradle\caches\transforms-2\files-2.1\d083c96bf16f0afa497f0903aac86f7e\constraintlayout-2.0.0-beta2\res\values\values.xml:290:5-295:36:
  AAPT: error: resource attr/motionProgress (aka
  com.myproject.myproject:attr/motionProgress) not found.
  C:\Users\me\.gradle\caches\transforms-2\files-2.1\d083c96bf16f0afa497f0903aac86f7e\constraintlayout-2.0.0-beta2\res\values\values.xml:318:5-232:
  AAPT: error: resource attr/motionProgress (aka
  com.myproject.myproject:attr/motionProgress) not found.
  C:\Users\me\.gradle\caches\transforms-2\files-2.1\d083c96bf16f0afa497f0903aac86f7e\constraintlayout-2.0.0-beta2\res\values\values.xml:322:5-335:98:
  AAPT: error: reso</p>
  </blockquote>