# Problems and Limitations

This page lists open HNBody bugs and limitations, and any other issues of which users should be aware.

## Open Bugs

These are the outstanding issues of which ordinary HNBody users should be aware. They are considered defects and will be resolved in a future release.

- The Symplectic integrator can fail for systems containing bodies on extremely hyperbolic orbits.

## Current Limitations

These are known feature limitations or usage restrictions applicable to the latest official release. They may (or may not) be relaxed or removed in a future release, as noted.

- The option to time-regularize ZWPs is currently disabled. This capability will be activated in release version 1.1.

- Symplectic integrations cannot resolve close encounters between particles. Support for this will be available in release version 1.2.

- Conversion from Cartesian coordinates to orbital elements can lose phase precision (due to round-off) for nearly-circular orbits. This does not affect simulated particle dynamics; however, output phase-related quantities such as the mean anomaly and argument of periapse may be inaccurate in certain cases.