Enabling the logs
Subversion ALM writes traces in the JIRA logs. However, this feature is disabled by default and you have to explicitly authorize the plugin for that:
JIRA > Administration > System > Troubleshooting & Support > Logging and Profiling > Default Loggers > Configure:
- Package Name: com.kintosoft.jira & com.kintosoft.svnwebclient (two packages)
- Logging Level: DEBUG
Please repeat the test and send the relevant traces for supporting.
Keep in mind that the configuration above is automatically reset if JIRA is re-started so you have to grant the plugin to write in the JIRA logs again.
The 404 Error
The Atlassian's JIRA Subversion plugin must be uninstalled.