Exception running when i‘m delete unused interface

[Yangqi0338]

Caused by: java.io.FileNotFoundException: class path resource [com/base/sbc/module/common/convert/OrderBookConvert.class] cannot be opened because it does not exist at org.springframework.core.io.ClassPathResource.getInputStream(ClassPathResource.java:172) ~[spring-core-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.core.type.classreading.SimpleMetadataReader.<init>(SimpleMetadataReader.java:50) ~[spring-core-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.core.type.classreading.SimpleMetadataReaderFactory.getMetadataReader(SimpleMetadataReaderFactory.java:102) ~[spring-core-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.boot.type.classreading.ConcurrentReferenceCachingMetadataReaderFactory.createMetadataReader(ConcurrentReferenceCachingMetadataReaderFactory.java:89) ~[spring-boot-1.5.10.RELEASE.jar:1.5.10.RELEASE] at org.springframework.boot.type.classreading.ConcurrentReferenceCachingMetadataReaderFactory.getMetadataReader(ConcurrentReferenceCachingMetadataReaderFactory.java:76) ~[spring-boot-1.5.10.RELEASE.jar:1.5.10.RELEASE] at org.springframework.core.type.classreading.SimpleMetadataReaderFactory.getMetadataReader(SimpleMetadataReaderFactory.java:80) ~[spring-core-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.context.annotation.ConfigurationClassParser.asSourceClass(ConfigurationClassParser.java:693) ~[spring-context-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.context.annotation.ConfigurationClassParser$SourceClass.getInterfaces(ConfigurationClassParser.java:870) ~[spring-context-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.context.annotation.ConfigurationClassParser.processInterfaces(ConfigurationClassParser.java:363) ~[spring-context-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.context.annotation.ConfigurationClassParser.doProcessConfigurationClass(ConfigurationClassParser.java:320) ~[spring-context-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.context.annotation.ConfigurationClassParser.processConfigurationClass(ConfigurationClassParser.java:245) ~[spring-context-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:190) ~[spring-context-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.context.annotation.ConfigurationClassParser.doProcessConfigurationClass(ConfigurationClassParser.java:292) ~[spring-context-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.context.annotation.ConfigurationClassParser.processConfigurationClass(ConfigurationClassParser.java:245) ~[spring-context-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:198) ~[spring-context-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:167) ~[spring-context-4.3.14.RELEASE.jar:4.3.14.RELEASE]

version
1.5.5.Final

[Yangqi0338]

When I delete the target folder, it's worked.
But can we not delete it?