Factorio Forums

edit: Duplicate of this issue: viewtopic.php?f=7&t=119600, will post any further updates to that thread

If I load _any_ previous save of my game before today the pipeline that should have light oil is blocked by petroleum. In some instances the machines using the light oil are still active with light oil in their buffers, meaning the pipeline was seemingly fine moments before the save was made. This is across saves that are hours apart, so if petroleum had erroneously entered the system in the previous save then the machines using the pipeline wouldn't still be active hours later.

I had previously encountered this twice before, first time I thought it was my mistake and fixed it, the 2nd time I assumed I accidentally continued from a save before I had fixed it, and now.

Difficult to say what triggers it. Possibly fixed in .14 as I can't reproduce it by simply saving and loading after draining the pipeline of petroleum (edit: to be clear, I haven't tested this in previous versions, just spitballing)... but the only things to do with fluids in patch notes for .14 are unrelated(?) (see below / linked thread for more info). Most recent save where there had obviously been light oil in the pipeline moments before the save was created is a 2.0.13 save from earlier today.

Seeing as this has not yet been filled as "not a bug" where other duplicate threads have been...

This IS an issue. A version change in the game will sometimes allow fluids to leak between pipelines. This is NOT a case of accidental rotation or connecting pipes incorrectly.