Although these problems have reduced significantly since the first version was released in 1997, sometimes there might still be problems with the operating system itself. In general there are two kinds of crashes: System crashes and Program crashes. Situations, in which ENVI-met fails to produce a solution but stops under controlled conditions are handled in the next section.

There are at least 1.001 reasons why WINDOWS can crash. You can lower the chance of crashes by doing the following things:

• Start your simulation with a “fresh” system. Turn the power of and one before you start ENVI-met.
• Close other programs, especially programs working in the background if you are low on memory.
• If you calculate huge models the best thing is to leave the computer and ENVI-met alone.
• Do you have enough memory? When WINDOWS starts swapping you are on the loosing path… It might not crash the system but makes the simulation quite slow…
• Is your CPU-van ok? Don't forget that the processor might work for hours with a 100% load… that might cause thermal trouble.
• Disable your screen saver. (This saves calculation time)

Different to system crashes, this means that you get an error message on the screen.

Under some conditions ENVI-met produces nonsense running under WINDOWS. This results mainly in Errors in Floating point calculations when the initial turbulence field is calculated or other abnormal termination during the initialization. This problem can sometimes overcome by turning off the computer and reboot it and then restart ENVI-met. Also, there might be thermal problem with your CPU - you should check this.

Another reason might be bad memory modules - especially when the last Byte of physical memory is used you might experience trouble you normally won't get. In fact, a buggy memory module is of course always buggy, but in other programs you might not see the effect.

Some other things to check, if your configuration does not work:

• If ENVI-met crashes at the beginning, check the log-output. Probably some files are missing. Use the “Check only” option to generate a check output.
• Check if your input files and database files are ok. Especially check, if all entries are well formatted like in the original file. Make sure that all files only contain *plain ASCII* text like NOTEPAD produces. DO NOT write any file in a word processor (e.g. MS WORD) and save it as a normal document. This will produce unreadable formatted files
• Have you always used the point “.” for your decimal numbers? The comma “,” is not a valid numeric operator!
• Is WINDOWS working properly? ENVI-met allocates huge areas of memory for data storing. If a program has “gone wild” or WINDOWS has had some serious problems before or during the model run, it might have happened that the stored data are destroyed. Don't run ENVI-met if you are low on memory. Make sure that ENVI-met runs in your physical memory NOT in swapped memory!
• ENVI-met produces numerical errors like “Error in Floating Point Expression”… This is bad. Something went wrong. If you are sure that all input files have been read properly and only contain valid values, and there has not been any system problem running WINDOWS (see above) then there is a problem with your model configuration. Also see next section. Sorry, no general solution for this available. Please contact me.