Childhood movie

Type: Movie/TV show/series/episode
It could be any of those, It's a vague memory, but it annoys me that I can't find the movie.
It was animated.

Plot:

A large group of teenagers go on a camping trip or some kind of adventure in the woods.
Part of the group enters a cave or underground area and discovers a diary from a boy who died many years ago.
They read a part of the diary that mentions the boy froze to death, with his last words being something like "my fingers are fro". He couldn't finish his sentence, because he was to cold and probably died. They flashback to that moment and the boy was sitting in a tree i think.
They also find a picture of a group from the same time period, which includes someone they know - a guy who has been with them throughout the trip. but this is not possible, because the diary and the picture are from long ago
Upon discovering the picture, the guy disappears, leading them to believe he was a ghost.
The diary and picture date back to the 1930s or 1940s. (i think, not sure)
There is also a scene involving boats on a river. (vague memory, maybe not relevant)
It watched it in the Dutch version, but i don't know from wich country it Originaly is.
It saw it between 2003 and 2010. but it is possible that the movie or tv-show is (much) older.
It may have been shown on Nickelodeon Belgium/netherlands or Ketnet.
It features all human characters, with no mythical creatures.
The last words in the diary were "mijn vingers zijn bevr" (in Dutch), which translates to "my fingers are frozen". That is the part that i'm most sure about. That's definitely in the movie/show/episode and perhaps near the end.

i hope someone can help me

Re: Nickelodeon show. Maybe Are You Afraid of the Dark? It definitely sounds like one of those episodes. There's a newer and older version, too.

Good suggestion!
But no, that was not it.
Also I am quite sure it was animated.

Chat bot ai says - It sounds like an episode from the animated TV show "Gravity Falls" titled "Into the Bunker" (season 2, episode 2).

In this episode, Dipper, Mabel, Wendy, and Soos go on a mission to explore an abandoned government bunker. While exploring the bunker, they find a diary written by a man named Quentin Trembley, who froze to death in the bunker. His last words were "My fingers are frosty."

They also find a photograph of Trembley's time, which includes a young man who looks exactly like Dipper's friend, Wendy's ex-boyfriend Robbie. They believe that Robbie might be a ghost, but it turns out that he is actually Trembley's descendant.

Additionally, there is a scene in which the group uses a boat to navigate a river while trying to escape from the bunker.

It also suggests an episode of scooby doo!!!

Also a good suggestion! But unfortunately gravity falls is not old enough. I’m not sure what year i saw it, but it was definitely before 2010-2011.
I also don’t find an episode from Scooby-Doo that seems like my story.

Chat bot ai gives another one - The movie or TV show you are describing is most likely the Nickelodeon TV movie "Mystery Mansion" (2004), also known as "Mystery Mansion: Het Geheim Van Het Spookhuis" in Dutch.

In the movie, a group of teenagers goes on a camping trip and stumbles upon an abandoned mansion. They decide to explore the mansion, and while doing so, they discover a diary from a boy who died many years ago. The diary mentions the boy freezing to death, with his last words being "mijn vingers zijn bevr" (my fingers are frozen).

The group also finds a picture of a group from the same time period, which includes someone they know - a guy who has been with them throughout the trip. This leads them to believe that he is a ghost.

The movie features all human characters, with no mythical creatures. It also includes a scene with boats on a river.

"Mystery Mansion" was a Nickelodeon TV movie and was shown on Nickelodeon Belgium and Netherlands, which matches your memory.

Thanks for all you efforts to help me. I really appreciate that! But unfortunately that’s also not the one I’m looking for. Also it’s not animated and I’m quite sure that the one I’m looking for is animated.