If when generating a site plan you get an error containing 'Not enough Memory' this is likely caused by Region setting, Date and Time Format settings. For site plans to work correctly you must have the Format settings set to English(United Kingdom).
To change this select Start and type 'Region Settings". Select Region Settings when it pops up as an option.
In the Window that opens select Additional Date, Time and Regional Settings from the right.
When the new window opens change the Format to English(United Kingdom)
Apply and save the new settings and restart the PC. After this when you try the site plan it should work correctly.