diff --git a/apps/jreleaser/src/main/java/org/jreleaser/cli/Checksum.java b/apps/jreleaser/src/main/java/org/jreleaser/cli/Checksum.java
index 84444abd..5d11fd70 100644
--- a/apps/jreleaser/src/main/java/org/jreleaser/cli/Checksum.java
+++ b/apps/jreleaser/src/main/java/org/jreleaser/cli/Checksum.java
@@ -18,7 +18,6 @@
 package org.jreleaser.cli;
 
 import org.jreleaser.model.JReleaserContext;
-import org.jreleaser.tools.Checksums;
 import picocli.CommandLine;
 
 /**
@@ -34,6 +33,6 @@ public class Checksum extends AbstractModelCommand {
     }
 
     static void checksum(JReleaserContext context) {
-        Checksums.collectAndWriteChecksums(context);
+        org.jreleaser.checksum.Checksum.collectAndWriteChecksums(context);
     }
 }
diff --git a/core/jreleaser-engine/src/main/java/org/jreleaser/tools/Checksums.java b/core/jreleaser-engine/src/main/java/org/jreleaser/checksum/Checksum.java
similarity index 96%
rename from core/jreleaser-engine/src/main/java/org/jreleaser/tools/Checksums.java
rename to core/jreleaser-engine/src/main/java/org/jreleaser/checksum/Checksum.java
index 6087d94d..33bc1bd4 100644
--- a/core/jreleaser-engine/src/main/java/org/jreleaser/tools/Checksums.java
+++ b/core/jreleaser-engine/src/main/java/org/jreleaser/checksum/Checksum.java
@@ -15,7 +15,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.jreleaser.tools;
+package org.jreleaser.checksum;
 
 import com.google.common.hash.HashCode;
 import com.google.common.hash.Hashing;
@@ -37,7 +37,7 @@ import static org.jreleaser.util.JReleaserLogger.DEBUG_TAB;
  * @author Andres Almiray
  * @since 0.1.0
  */
-public class Checksums {
+public class Checksum {
     public static void collectAndWriteChecksums(JReleaserContext context) throws JReleaserException {
         context.getLogger().info("Calculating checksums");
 
@@ -56,6 +56,11 @@ public class Checksums {
             }
         }
 
+        if (checksums.isEmpty()) {
+            context.getLogger().info("No files configured for checksum. Skipping");
+            return;
+        }
+
         Path checksumsFilePath = context.getChecksumsDirectory().resolve("checksums.txt");
         try {
             Files.createDirectories(context.getChecksumsDirectory());
diff --git a/core/jreleaser-engine/src/main/java/org/jreleaser/sign/Signer.java b/core/jreleaser-engine/src/main/java/org/jreleaser/sign/Signer.java
index 716960fa..ccc97b72 100644
--- a/core/jreleaser-engine/src/main/java/org/jreleaser/sign/Signer.java
+++ b/core/jreleaser-engine/src/main/java/org/jreleaser/sign/Signer.java
@@ -73,13 +73,17 @@ public class Signer {
     public static void sign(JReleaserContext context) throws SigningException {
         context.getLogger().info("Signing files");
         if (!context.getModel().getSigning().isEnabled()) {
-            context.getLogger().info("Signing is not enabled");
+            context.getLogger().info("Signing is not enabled. Skipping");
+            return;
+        }
+
+        List<Path> paths = collectArtifactsForSigning(context);
+        if (paths.isEmpty()) {
+            context.getLogger().info("No files configured for signing. Skipping");
             return;
         }
 
         InMemoryKeyring keyring = createInMemoryKeyring(context.getModel().getSigning());
-
-        List<Path> paths = collectArtifactsForSigning(context);
         List<FilePair> files = sign(context, keyring, paths);
         verify(context, keyring, files);
     }
diff --git a/core/jreleaser-engine/src/main/java/org/jreleaser/tools/DistributionProcessor.java b/core/jreleaser-engine/src/main/java/org/jreleaser/tools/DistributionProcessor.java
index ef35c3cb..439e277d 100644
--- a/core/jreleaser-engine/src/main/java/org/jreleaser/tools/DistributionProcessor.java
+++ b/core/jreleaser-engine/src/main/java/org/jreleaser/tools/DistributionProcessor.java
@@ -17,6 +17,7 @@
  */
 package org.jreleaser.tools;
 
+import org.jreleaser.checksum.Checksum;
 import org.jreleaser.model.Artifact;
 import org.jreleaser.model.Distribution;
 import org.jreleaser.model.JReleaserContext;
@@ -72,7 +73,7 @@ public class DistributionProcessor {
         context.getLogger().debug("Reading checksums for {} distribution", distributionName);
         for (int i = 0; i < distribution.getArtifacts().size(); i++) {
             Artifact artifact = distribution.getArtifacts().get(i);
-            Checksums.readHash(context, distributionName, artifact);
+            Checksum.readHash(context, distributionName, artifact);
         }
 
         return ToolProcessors.findProcessor(context, tool)
diff --git a/core/jreleaser-engine/src/main/java/org/jreleaser/tools/Distributions.java b/core/jreleaser-engine/src/main/java/org/jreleaser/tools/Distributions.java
index d4636dd1..16bbc9cc 100644
--- a/core/jreleaser-engine/src/main/java/org/jreleaser/tools/Distributions.java
+++ b/core/jreleaser-engine/src/main/java/org/jreleaser/tools/Distributions.java
@@ -32,6 +32,11 @@ import java.util.stream.Collectors;
  */
 public class Distributions {
     public static void process(JReleaserContext context, boolean failFast, String action, ToolProcessingFunction function) {
+        if (context.getModel().getDistributions().isEmpty()) {
+            context.getLogger().debug("No configured distributions [" + action.toLowerCase() + "]. Skipping");
+            return;
+        }
+
         context.getLogger().info("{} distributions", action);
         List<Exception> exceptions = new ArrayList<>();
         for (Distribution distribution : context.getModel().getDistributions().values()) {
diff --git a/core/jreleaser-model/src/main/java/org/jreleaser/model/JReleaserModelValidator.java b/core/jreleaser-model/src/main/java/org/jreleaser/model/JReleaserModelValidator.java
index 7f48fac7..5f7e3b1b 100644
--- a/core/jreleaser-model/src/main/java/org/jreleaser/model/JReleaserModelValidator.java
+++ b/core/jreleaser-model/src/main/java/org/jreleaser/model/JReleaserModelValidator.java
@@ -411,11 +411,6 @@ public final class JReleaserModelValidator {
     private static void validateDistributions(JReleaserContext context, List<String> errors) {
         Map<String, Distribution> distributions = context.getModel().getDistributions();
 
-        if (distributions.isEmpty()) {
-            errors.add("Missing distributions configuration");
-            return;
-        }
-
         if (distributions.size() == 1) {
             distributions.values().stream()
                 .findFirst().ifPresent(distribution -> distribution.setName(context.getModel().getProject().getName()));
diff --git a/core/jreleaser-model/src/main/java/org/jreleaser/model/releaser/spi/AbstractReleaserBuilder.java b/core/jreleaser-model/src/main/java/org/jreleaser/model/releaser/spi/AbstractReleaserBuilder.java
index 44701796..5589b596 100644
--- a/core/jreleaser-model/src/main/java/org/jreleaser/model/releaser/spi/AbstractReleaserBuilder.java
+++ b/core/jreleaser-model/src/main/java/org/jreleaser/model/releaser/spi/AbstractReleaserBuilder.java
@@ -70,9 +70,6 @@ public abstract class AbstractReleaserBuilder<R extends Releaser, B extends Rele
 
     protected void validate() {
         requireNonNull(context, "'context' must not be null");
-        if (assets.isEmpty()) {
-            throw new IllegalArgumentException("'assets must not be empty");
-        }
     }
 
     @Override
diff --git a/plugins/jreleaser-ant-tasks/src/main/java/org/jreleaser/ant/tasks/JReleaserChecksumTask.java b/plugins/jreleaser-ant-tasks/src/main/java/org/jreleaser/ant/tasks/JReleaserChecksumTask.java
index 80a7ef4b..8467bf0b 100644
--- a/plugins/jreleaser-ant-tasks/src/main/java/org/jreleaser/ant/tasks/JReleaserChecksumTask.java
+++ b/plugins/jreleaser-ant-tasks/src/main/java/org/jreleaser/ant/tasks/JReleaserChecksumTask.java
@@ -18,7 +18,7 @@
 package org.jreleaser.ant.tasks;
 
 import org.jreleaser.model.JReleaserContext;
-import org.jreleaser.tools.Checksums;
+import org.jreleaser.checksum.Checksum;
 
 /**
  * @author Andres Almiray
@@ -31,6 +31,6 @@ public class JReleaserChecksumTask extends AbstractJReleaserTask {
     }
 
     static void checksum(JReleaserContext context) {
-        Checksums.collectAndWriteChecksums(context);
+        Checksum.collectAndWriteChecksums(context);
     }
 }
diff --git a/plugins/jreleaser-gradle-plugin/src/main/groovy/org/jreleaser/gradle/plugin/tasks/JReleaserChecksumTask.groovy b/plugins/jreleaser-gradle-plugin/src/main/groovy/org/jreleaser/gradle/plugin/tasks/JReleaserChecksumTask.groovy
index e8f85c78..feca79cb 100644
--- a/plugins/jreleaser-gradle-plugin/src/main/groovy/org/jreleaser/gradle/plugin/tasks/JReleaserChecksumTask.groovy
+++ b/plugins/jreleaser-gradle-plugin/src/main/groovy/org/jreleaser/gradle/plugin/tasks/JReleaserChecksumTask.groovy
@@ -21,7 +21,7 @@ import groovy.transform.CompileStatic
 import org.gradle.api.model.ObjectFactory
 import org.gradle.api.tasks.TaskAction
 import org.jreleaser.model.JReleaserContext
-import org.jreleaser.tools.Checksums
+import org.jreleaser.checksum.Checksum
 
 import javax.inject.Inject
 
@@ -43,6 +43,6 @@ abstract class JReleaserChecksumTask extends AbstractJReleaserTask {
     }
 
     static void checksum(JReleaserContext context) {
-        Checksums.collectAndWriteChecksums(context)
+        Checksum.collectAndWriteChecksums(context)
     }
 }
diff --git a/plugins/jreleaser-maven-plugin/src/main/java/org/jreleaser/maven/plugin/JReleaserChecksumMojo.java b/plugins/jreleaser-maven-plugin/src/main/java/org/jreleaser/maven/plugin/JReleaserChecksumMojo.java
index a48a9dc2..3e1291a6 100644
--- a/plugins/jreleaser-maven-plugin/src/main/java/org/jreleaser/maven/plugin/JReleaserChecksumMojo.java
+++ b/plugins/jreleaser-maven-plugin/src/main/java/org/jreleaser/maven/plugin/JReleaserChecksumMojo.java
@@ -23,7 +23,7 @@ import org.apache.maven.plugins.annotations.Mojo;
 import org.apache.maven.plugins.annotations.Parameter;
 import org.jreleaser.model.JReleaserContext;
 import org.jreleaser.model.JReleaserException;
-import org.jreleaser.tools.Checksums;
+import org.jreleaser.checksum.Checksum;
 
 /**
  * @author Andres Almiray
@@ -47,7 +47,7 @@ public class JReleaserChecksumMojo extends AbstractJReleaserMojo {
 
     static void checksum(JReleaserContext context) throws MojoExecutionException {
         try {
-            Checksums.collectAndWriteChecksums(context);
+            Checksum.collectAndWriteChecksums(context);
         } catch (JReleaserException e) {
             throw new MojoExecutionException("Unexpected error writing checksums", e);
         }
diff --git a/sdks/github-java-sdk/src/main/java/org/jreleaser/sdk/github/Github.java b/sdks/github-java-sdk/src/main/java/org/jreleaser/sdk/github/Github.java
index b65a2717..8255b210 100644
--- a/sdks/github-java-sdk/src/main/java/org/jreleaser/sdk/github/Github.java
+++ b/sdks/github-java-sdk/src/main/java/org/jreleaser/sdk/github/Github.java
@@ -30,6 +30,7 @@ import org.kohsuke.github.GitHub;
 import org.kohsuke.github.GitHubBuilder;
 
 import java.io.IOException;
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.List;
 
@@ -108,8 +109,8 @@ class Github {
 
     void uploadAssets(GHRelease release, List<Path> assets) throws IOException {
         for (Path asset : assets) {
-            if (0 == asset.toFile().length()) {
-                // do not upload empty files
+            if (0 == asset.toFile().length() || !Files.exists(asset)) {
+                // do not upload empty or non existent files
                 continue;
             }
 
diff --git a/sdks/github-java-sdk/src/main/java/org/jreleaser/sdk/github/GithubReleaser.java b/sdks/github-java-sdk/src/main/java/org/jreleaser/sdk/github/GithubReleaser.java
index 8db94206..dda9c762 100644
--- a/sdks/github-java-sdk/src/main/java/org/jreleaser/sdk/github/GithubReleaser.java
+++ b/sdks/github-java-sdk/src/main/java/org/jreleaser/sdk/github/GithubReleaser.java
@@ -28,6 +28,7 @@ import org.kohsuke.github.GHRelease;
 import org.kohsuke.github.GHRepository;
 
 import java.io.IOException;
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.List;
@@ -108,8 +109,8 @@ public class GithubReleaser implements Releaser {
 
         if (context.isDryrun()) {
             for (Path asset : assets) {
-                if (0 == asset.toFile().length()) {
-                    // do not upload empty files
+                if (0 == asset.toFile().length() || !Files.exists(asset)) {
+                    // do not upload empty or non existent files
                     continue;
                 }