Known Issues

If NetLogo malfunctions, please send us a bug report. See the "Contact Us" section for instructions.

Known bugs (all systems)

• Integers in NetLogo must lie in the range -2147483648 to 2147483647; if you exceed this range, instead of a runtime error occurring, you get incorrect results
• Out-of-memory conditions are not handled gracefully
• The run and runresult primitives do not work properly if their input contains any uses of the special variables ?, ?1, ?2, etc. (we are already working on fixing this)
• The stop command does not work properly if used inside without-interruption (we are already working on fixing this)
• If you use "Export World" to suspend a model run and then resume it later with "Import World", this may change the outcome of the model run if your model involves turtles dying and new turtles being born, because the export/import may change what who numbers get assigned to new turtles (we are already working on fixing this)
• Extensions don't work from models saved as applets (we are already working on fixing this)

Windows-only bugs

• The "User Manual" item on the Help menu does not work on every machine (Windows 98 and ME are most likely to be affected, newer Windows versions less so)
• On some laptops, the Procedures and Info tabs may become garbled when you scroll them. To avoid this bug, reduce the size of the NetLogo window and/or reduce the color depth of your monitor (e.g. change from 32-bit to 16- or 8-bit color). This is a bug in Java itself, not in NetLogo per se. For technical details on the bug, see http://developer.java.sun.com/developer/bugParade/bugs/4763448.html (free registration required). NetLogo users are encouraged to visit that site and vote for Sun to fix this bug.
• The sound extension is not compatible with Java VM version 1.4.2_06, which does not include the default soundbank file. If you choose the "with VM" option when downloading NetLogo, you will get version 1.4.2_05 of the VM, which does not have the problem. We are waiting to see if Sun will fix this issue in their 1.4.2_07 release, or whether we will need to provide a workaround for 1.4.2_06 users.

Macintosh-only bugs

• When opening a model from the Finder (by double-clicking on it, or dragging it onto the NetLogo icon), if NetLogo is not already running, then the model may or may not open (the bug is intermittent). If NetLogo is already running, the model always opens.
• It is possible for NetLogo's menus to get confused so that the "Quit" item does not work. If this happens, you can quit NetLogo by pressing the red close button on the left end of the NetLogo's title bar.
• On OS X 10.2, the "User Manual" item on the Help menu will sometimes launch a web browser other than your default browser

Linux/UNIX-only bugs

• User Manual always opens in Netscape, not your default browser. One possible workaround is to bookmark the file docs/index.html in your favorite browser. Another workaround is to make a symlink that's called "netscape" (that's the command name NetLogo tries to run), but actually runs a different browser.
• We have discovered a problem on Linux where the "exp" reporter sometimes returns a slightly different answer (differing only in the last decimal place) for the same input. According to an engineer at Sun, this should only happen on Linux kernel versions 2.4.19 and earlier. We assume the problem is Linux-specific and does not happen on other Unix flavors. We are not sure if the problem ever occurs in practice during actual NetLogo model runs, or only occurs in the context of our testing regimen. The bug in the Sun's Java VM, and not in NetLogo itself. We hope that only the "exp" reporter is affected, but we can't be entirely certain of this. NetLogo users are encouraged to visit http://developer.java.sun.com/developer/bugParade/bugs/5023712.html (free registration required) and vote for Sun to fix this bug.

Known issues with computer HubNet

Unimplemented StarLogoT primitives

The following StarLogoT primitives are not available in NetLogo. (Note that many StarLogoT primitives, such as count-turtles-with, are intentionally not included in this list because NetLogo allows for the same functionality with the new agentset syntax.)

• maxint, minint, maxnum, minnum
• readlist
• import-turtles, import-patches, import-turtles-and-patches (note that NetLogo adds import-world, though)
• miscellaneous seldom-used plotting reporters such as plot-pencolor, pp-plotlist, pp-plotpointlist, ppinterval, ppxcor, ppycor, etc.
• bit, bitand, bitneg, bitor, bitset, bitstring, bitxor, make-bitarray, rotate-left, rotate-right, shift-left, shift-right
• load-pict (but see the Image Import Example model)
• camera-brightness, camera-click, camera-init, camera-set-brightness
• netlogo-directory, project-directory, project-name, project-pathname, save-project