Opentaps ERP- ClassNotFoundException error during running <p>Hi I am new to openTaps ERP development just a day before I started it.I have install a previously done project in my eclips.When I run it it gives me following error.I dont understand that error.</p> <p>what should be done?</p> <p>(I am using Postgresql database in it)</p> <pre><code>Exception in thread "main" java.lang.NoClassDefFoundError: org/slf4j/LoggerFactory at org.hibernate.cfg.Configuration.&lt;clinit&gt;(Configuration.java:152) at org.opentaps.foundation.infrastructure.Infrastructure.getSessionFactory(Infrastructure.java:120) at org.opentaps.common.container.HibernateContainer.start(HibernateContainer.java:109) at org.ofbiz.base.container.ContainerLoader.start(ContainerLoader.java:102) at org.ofbiz.base.start.Start.startStartLoaders(Start.java:264) at org.ofbiz.base.start.Start.startServer(Start.java:313) at org.ofbiz.base.start.Start.start(Start.java:317) at org.ofbiz.base.start.Start.main(Start.java:400) Caused by: java.lang.ClassNotFoundException: org.slf4j.LoggerFactory at java.net.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) ... 8 more </code></pre> <p>Anyone knows how to resolve it??</p>