Don't always complain for missing fields.

chemclipse/plugins/org.eclipse.chemclipse.support/src/org/eclipse/chemclipse/support/settings/parser/SettingsClassParser.java

@@ -34,11 +34,11 @@
 import org.eclipse.chemclipse.support.settings.SystemSettings;
 import org.eclipse.chemclipse.support.settings.SystemSettingsStrategy;
 import org.eclipse.chemclipse.support.settings.ValidatorSettingsProperty;
+import org.eclipse.chemclipse.support.settings.validation.EmptyStringValidator;
 import org.eclipse.chemclipse.support.settings.validation.EvenOddValidatorByte;
 import org.eclipse.chemclipse.support.settings.validation.EvenOddValidatorInteger;
 import org.eclipse.chemclipse.support.settings.validation.EvenOddValidatorLong;
 import org.eclipse.chemclipse.support.settings.validation.EvenOddValidatorShort;
-import org.eclipse.chemclipse.support.settings.validation.InputValidator;
 import org.eclipse.chemclipse.support.settings.validation.MinMaxValidator;
 import org.eclipse.chemclipse.support.settings.validation.RegularExpressionValidator;
 import org.eclipse.core.databinding.validation.IValidator;
@@ -128,7 +128,7 @@ public List<InputValue> getInputValues() {
 						for(Annotation annotation : annotations) {
 							if(annotation instanceof JsonProperty jsonProperty) {
 								if(jsonProperty.required()) {
-									inputValue.addValidator(new InputValidator(inputValue));
+									inputValue.addValidator(new EmptyStringValidator());
 								}
 							}
 							if(annotation instanceof LabelProperty labelProperty) {

chemclipse/plugins/org.eclipse.chemclipse.support/src/org/eclipse/chemclipse/support/settings/validation/EmptyStringValidator.java

@@ -0,0 +1,37 @@
+/*******************************************************************************
+ * Copyright (c) 2023 Lablicate GmbH.
+ * 
+ * All rights reserved.
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ * 
+ * Contributors:
+ * Matthias Mailänder - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.chemclipse.support.settings.validation;
+
+import org.eclipse.core.databinding.validation.IValidator;
+import org.eclipse.core.databinding.validation.ValidationStatus;
+import org.eclipse.core.runtime.IStatus;
+
+public class EmptyStringValidator implements IValidator<Object> {
+
+	private static final String ERROR = "Please enter a value.";
+
+	public EmptyStringValidator() {
+
+	}
+
+	@Override
+	public IStatus validate(Object value) {
+
+		if(value == null) {
+			return ValidationStatus.error(ERROR);
+		}
+		if(value instanceof String text && text.isEmpty()) {
+			return ValidationStatus.error(ERROR);
+		}
+		return ValidationStatus.ok();
+	}
+}

chemclipse/plugins/org.eclipse.chemclipse.support/src/org/eclipse/chemclipse/support/settings/validation/InputValidator.java

@@ -37,8 +37,6 @@ public IStatus validate(Object value) {
 		String message = null;
 		if(value == null) {
 			message = ERROR;
-		} else if(value instanceof String text && text.isEmpty()) {
-			message = ERROR;
 		} else {
 			Class<?> rawType = inputValue.getRawType();
 			if(rawType != null) {
@@ -65,7 +63,7 @@ private String parse(Class<?> rawType, String value) {
 				}
 			} else if(rawType == File.class) {
 				FileSettingProperty property = inputValue.getFileSettingProperty();
-				if(property != null && !(property.dialogType() == DialogType.SAVE_DIALOG)) {
+				if(property != null && property.dialogType() != DialogType.SAVE_DIALOG) {
 					if(value != null && !value.isEmpty() && !new File(value).exists()) {
 						return "Location does not exits, please choose a valid location";
 					}