Given the source:
@startuml
package A
{
package B
{
package C
{
package D
{
package E
{
component "E1"
component "E2"
component "E3"
}
}
}
}
}
@enduml
the plantUML parser fails with
[From string(line 12))] [...] Use 'allow mixing' if you want to mix classes and other UML elements
This fails both in online plantUML as well as in IntelliJ plugin.