Hey all,
We recently ran into some issues while trying to run the Remove Duplicate Centerlines process in our Roads and Highways implementation, which is currently using ArcGIS 10.5.1. I figured I'd document it here in case someone else encounters a similar problem.
There were two attempts to run the tool that halted due to error. The slightly confusing part is that both of these runs had a different error message. The first had a message stating "An expression of non-boolean type specified in a context were a condition is expected, near ','.
And the second run had this message, stating "Unable to update original centerlines: Sequence contains no matching element"