diff --git a/gradle/validation/validate-source-patterns.gradle b/gradle/validation/validate-source-patterns.gradle
index b4c1f899535..540ee2962fc 100644
--- a/gradle/validation/validate-source-patterns.gradle
+++ b/gradle/validation/validate-source-patterns.gradle
@@ -173,8 +173,22 @@ class ValidateSourcePatternsTask extends DefaultTask {
     def validSPINameJavadocTag = ~$/(?s)\s*\*\s*@lucene\.spi\s+\{@value #NAME\}/$;
 
     def isLicense = { matcher, ratDocument ->
-      licenseMatcher.reset()
-      return lineSplitter.split(matcher.group(1)).any { licenseMatcher.match(ratDocument, it) }
+      boolean retValue = false
+      Exception rethrow = null
+      int retries = 5
+      do {
+        try {
+          licenseMatcher.reset()
+          retValue = lineSplitter.split(matcher.group(1)).any { licenseMatcher.match(ratDocument, it) }
+          if (retValue) break
+        } catch (StringIndexOutOfBoundsException | RuntimeException e) {
+          logger.error("Exception thrown=" + e + ", retries: " + retries + ", matcher.group(1)=" + matcher.group(1))
+          rethrow = e
+        }
+      } while (retries-- > 0)
+      
+      if (rethrow != null) throw rethrow
+      return retValue
     }
 
     def checkLicenseHeaderPrecedes = { f, description, contentPattern, commentPattern, text, ratDocument ->
@@ -204,11 +218,12 @@ class ValidateSourcePatternsTask extends DefaultTask {
     progress.start(this.name, this.name)
 
     sourceFiles.each { f ->
-      try {
-        progress.progress("Scanning ${f.name}")
-        logger.debug('Scanning source file: {}', f);
+      progress.progress("Scanning ${f.name}")
+      logger.debug('Scanning source file: {}', f);
 
-        def text = f.getText('UTF-8');
+      def text = f.getText('UTF-8');
+
+      try {
         invalidPatterns.each { pattern, name ->
           if (pattern.matcher(text).find()) {
             reportViolation(f, name);
@@ -257,7 +272,7 @@ class ValidateSourcePatternsTask extends DefaultTask {
         }
       } catch (e) {
         e.printStackTrace()
-        throw new GradleException("Unhandled exception while validating patterns on file: " + f, e)
+        throw new GradleException("Unhandled exception while validating patterns on file: " + f + ", content: >>" + text + "<<", e)
       }
     }