Hi all,
we find this "issue" using GAP 3.1.0
Obsolete custom lint check
butterknife-8.5.1.aar/.../lint.jar: Lint found one or more custom checks that could not be loaded. The most likely reason for this is that it is using an older, incompatible or unsupported API in lint. Make sure these lint checks are updated to the new APIs. The issue registry class is butterknife.lint.LintRegistry. The class loading issue is com/android/tools/lint/detector/api/Detector$JavaPsiScanner: ClassLoader.defineClass1(ClassLoader.java:-2)鈫怌lassLoader.defineClass(ClassLoader.java:763)鈫怌lassLoader.defineClass(ClassLoader.java:642)鈫怳rlClassLoader._de
I also see the same with v8.8.1

On version 10.2.1:
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Lint found an issue registry (butterknife.lint.LintRegistry) which is older than the current API level; these checks may not work correctly.
Recompile the checks against the latest version. Custom check API version is 2 (3.2), current lint API level is 6 (3.6+)
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Most helpful comment
I also see the same with v8.8.1
