The error message means your project was too big to export in one try. A routine could not allocate more memory to finish the export.
You will need to break your project into parts and export those separately. You might also look for objects that have an unusual number of polygons and either simplify them or remove them from the export if they are unnecessary for your specific goal.
In AC 16 hotfix 2 the ifc export was significantly improved. Many projects that could not be exported due to size in AC 15 can be in AC 16. You might want to try opening the project hotfix 2 of AC 16 and exporting from there.
Hope this helps,
Ed
Graphisoft Technical Support