Can you provide more details about your system, verssion of Premiere, and the exact type of media file you are trying to import? We need a bit nore information to help you. Often times this error can be resolved with a version update or else the media you're trying to import is not a compatible format.
as John requestsed, Please tell us your system specs: OS version, Premiere version, amount of RAM, Hardware specs including graphics card and your source properties and sequence settings. Not sure why you think it's a memory issue but you might tell us what your preferences: memory settings are. If you don't have sufficient memory reserved for your operating system, you can have issues.