This one should almost be obvious from the description if someone has used blue ocean. 

It is possible to get a run that fails very early on, but there are no reasonable flownodes, thus no steps, no stages, and useless blue ocean results screen. 

In this case it should just show the full log (or the last N lines) vs failing the user. 

One way to reproduce a subset of this would be to use a pipeline like the following. When clicking on a branch, it says "no steps" - this should fall back to showing the full log in the error case. 

In the case where there is just one stage and in error but no steps - same applies. When there are no stages and in error - same applies. show log. 
node {
def hello_message = "Hello" stage('Fake1') {
parallel firstBranch: {
sh "echo ${helo_message}" }, secondBranch: {
sh "echo ${hello_message}" }
}
}