If you're running OFP version 1.30 or above, click on OPTIONS from OFP's main menu. Then click on VIDEO OPTIONS and disable MULTI-TEXTURING. See if that resolves your problem. If it does, be aware that this may cause a minor side effect in some cases.
If you're running an earlier version of OFP or if the above suggestion didn't help, this has often been reported as being caused by using old graphics adapter drivers. Installing the latest driver version for your graphics card may resolve this problem.