After running `mvn eclipse:eclipse` this morning, we got a warning from eclipse, telling us that “Build path specifies execution environment J2SE-1.5. There are no JREs in the workspace strictly compatible with this environment.” We didn’t make any changes that could cause this warning, though. We deceided to leave the problem as it was and fix it later – it’s only a warning anyway. However, when trying to start another project, I got another exception I haven’t ever received before. It was caused by mixing up wrong versions of different slf4j JARs.