Assuming you have correctly upgraded to version 1.30 or above, this seems to be a bug.
If you're trying to have a resistance soldier or a civilian use the LTD, this will cause OFP to CTD. Ondrej Spanel, BIS' lead programmer, confirmed this bug and said that it will not be corrected in the immediate future.
If you're having this problem with west soldier units, some players report resolving this problem by either removing the usage of HW T&L in the OFP preferences program's DISPLAY DEVICE field or by maximizing the resolution and all advanced settings in the OFP preferences program.
If none of the above helps, read BIS's instructions to report CTD errors like this one.
Some people have a different problem with the LTD. If you can't see the LTD and/or your soldier spins around while holding the LTD, then your install is messed up. I know - I've been there.