Groovy/Grails error when upgrading from 2.0.4 to 2.2.1



Hi! I have a project that was initially for grails 2.0.4, but now I have upgraded to grails 2.2.1. The problem is that the project does not run anymore. I keep getting the error

Message: Error creating bean with name 'grailsApplication' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is org.codehaus.groovy.grails.exceptions.GrailsConfigurationException: Class not found loading Grails application: PlatformUiFIlters

when I try to run the program. I have cleaned the project and upgraded it to groovy 2.2.1. Any ideas on how to solve this?