Hi Jorge and welcome to the user to user forums. Assuming your video editor is Movie Edit Pro (also know as Video Deluxe) Your video files are probably from a smartphone, and probably an iPhone but could be another make manufacturers and a relatively new phone. The files have to be recorded at a constant frame rate and such phones often record at a variable frame rate that a Windows machine finds difficult to use and probably the files need converting to a constant frame rate before they will play in a Windows based video editing program.
File conversions can be done with tools such as Handbrake.
If it is not that then it could be your computer system does not meet the complete minimum requirements needed to run the program.
We need more information - computer specification, program full name and version number - please quote processor and graphics card names and model in full - see this topic for more details of what is required.
A MediaInfo analysis of one of the source videos would also help - post the results from the Text view in MediaInfo.
Precisamos de mais informações - especificações do computador, nome completo do programa e número da versão - cite os nomes do processador e da placa gráfica e o modelo completo - consulte este tópico para obter mais detalhes sobre o que é necessário.
Uma análise do MediaInfo de um dos vídeos de origem também ajudaria - postar os resultados da visualização Texto no MediaInfo.