Error: "F" is not a valid character for a file-based resource name: file-based resource names should contain only lowercase az, 0-9, or underscore

Question

Error:

'F' is not a valid file-based resource name character: File-based resource names must contain only lowercase az, 0-9, or underscore

  <?xml version="1.0" encoding="utf-8"?> <set xmlns:android="http://schemas.android.com/apk/res/android"> <alpha android:duration="2000" android:fromAlpha="0.0" android:toAlpha="1.0" android:interpolator="@android:anim/accelerate_interpolator" /> </set> 

Where is the mistake? I do not see

Answer 1

The error is not in the XML code, but in the file name. Check the file names in your res! Directories It seems that one of the files has its capital "F" in the file name.