Unlike in the movie where Böttger first met King August the Strong in 1701, the first meeting of the two was in January 1704 after pure conversation via mail first.
The view of the Albrechtsburg Meißen at the end of the movie is incorrect, e.g the windows of the right tower look different in real life. The top window is half round while in the movie it is the same as the below ones.
According to sources Ehrenfried von Tschirnhaus and Johann Friedrich Böttger didn't meet until March 1702 in Dresden, while in the movie they meet in Berlin in September 1701.
The Hotel "König von Preußen" (King of Prussia) didn't exist until 1740 and it was called "Hotel Montgobert" at that time. It was named "König von Preußen" only in 1824. The scene is set however in 1701.
King Frederic I is announced as "King of Prussia". This title didn't exist until 1772. Until then all Prussian kings were titled as "King in Prussia".
When meeting Böttger in his workshop August The Sttong has two dalmatians with him. While these dogs in the 18th century the first spreading of dalmatians in the German regions was in the late 19th century, with the first reference in Braunschweig in 1885.
The hotel guest book shows the hotel name "Hotel King of Portugal". While a hotel existed at that place during the time setting (September 1701) it didn't got its shown name after King Frederic Wilhelm I accommodated a Portugese delegation there. Frederic Wilhelm I didn't become King until 1713.
When talking to Katharina, von Tschirnhausen mentioned Salami. The first Salami came from Italy first to Austria in the lat 18th century and didn't enter the German regions until the 19th century. The scene however is set in 1701.
When arriving at the hotel Ehrenfried von Tschirnhaus introduces himself as "Tschirnhausen".