Set your Windows virtual swap file's maximum size to 1000. Reboot and see if that resolves the problem.
If you've tried the above and continue to have this problem with OFP: Resistance, and you've increased the VISIBILITY setting in the VIDEO OPTIONS menu, try resetting VISIBILITY back to the default of 900 meters.
If you've installed Kegetys' Editor Addon, make sure you have the latest version, as older versions may result in these error messages.
OFP player madmedic encountered this error message when he inadvertently defined too many magazines for a unit in a mission he was editing.
If none of the above has resolved your problem and you're up the creek without a paddle, follow these instructions for contacting BIS support directly.