Goofs

When Harry emerges from the woods and catches the train to Riga, it is indicated the trip lasted a while. However, when the train comes to a halt, it is still on the same small part of the track where he got on board, just filmed from another angle and a bit further on. The same red wooden huts can be seen across the river (old town Porvoo).

Viruses cannot be seen in an optical microscope (except perhaps as tiny dots).

The "viruses" as seen through the microscope are actually bacteria.

When the virus-loaded eggs are examined in the secret lab, they are extracted from an egg with the yolk. Viruses when bred in eggs do not reproduce in the yolk but in the cells of the living chicken embryo.

In the credits $1,000,000,000,000,000,000 is written. This is neither the American billion (a thousand million) nor the British billion of old (a million million) but is in fact a quintillion.

The ice that breaks up under the invading force is not pure white. The edges appear brown and dirty indicating that the ice is not formed from sea water.

When Harry Palmer is being taken to the concert, he passes a sign in Russian that says "Mopchdt", which is a meaningless, unpronounceable misspelling of "Molchat" meaning "silence".

Train wagon in Russia was marked VR which is Finnish Railways acronym meaning Valtion Rautatiet.

Train cars are not bound by international borders. A Finnish car is allowed to be in Russia.

When Palmer and Newbigen are removed from the Helskini-Moscow train, Anya removes a pistol from her pocket, and fires nine rounds, killing Midwinter's two stooges. The gun she pulled was a Smith and Wesson "Bodyguard" which holds just five shots.

As a plane lands on and skids on ice/snow, the sound is of tires skidding onto a concrete runway.

When the 'ice floes' tilt out of the water during the battle sequence, the metal frames they are built on becomes visible.

After General Midwinter gets in his troop transport - disguised as a fuel tanker - another one is shown closing its rear hatch. A reflection of the camera, its platform, and a crew member is visible on said hatch.

When Palmer is first taken to the computer room in Helsinki, the paper seen going in to the bottom of the printer already has text printed on it, instead of being blank.