In the past, when I used Cisco packet tracer I was just able to take, for example, one Computer, use the black wire and connect it to another computer. Without any extra changes it would connect. But this doesn't seem to work now, but strangely I can connect some devices (such as switches and Servers - but not Switches and Computers).
Here is what I tried out: Picture of what I tried out
It would be amazing if somebody could help me.
When you connect device of the same type with an Ethernet Cable, such as Computer-Computer Switch-Switch Router-Router or Router-Computer, you need a crossover cable(EIA/TIA 568B) (black dotted line icon in the PacketTracer). If you would to leave the choise to Packet Tracer you can choose the thunderbolt icon in the connection menu, but I do not recommend it because you need to learn.
