The file g3d.dll is part of Microsoft Flight Simulator created by Microsoft Corporation. When you get an error with this file, it usually indicates a problem with your add-on scenery. While reinstalling the scenery sometimes solves the issue, sometimes other files come into play making this a complicated problem to solve.
Some users have discovered that an error that lists this file actually indicates an issue with their video card drivers. Make sure your drivers and your scenery are all updated to the latest version, and clean your registry to be sure to fix this one. Cleaning your registry can help in this case because the problem may be with the g3d dynamic link library file or with another file referenced by the registry.
Targeting the g3d.dll file’s entry alone may not solve the issue. ZookaWare PC Cleaner scans your entire registry, fixing every error for you. ZookaWare PC Cleaner is guaranteed to find and repair every registry problem, so give it a try if you run into this error. ZookaWare PC Cleaner will get you flying again.