I saved a Farm Layout Plan for Oysters (RealWorld) but after playing a single vanilla game and returning to RealWorld, that Farm Layout Plan had changed.
It was saved with 4 sets of Livestock Raising+Livestock Processing linked to a single Sales units.
But one of the Raising units was gone and two of them unassigned. The Proccesing units linked to the now missing unit, and one linked to an unassigned processing unit were still set to procees Oysters and the two other were unassigned.
Being saved with 4 valid production chains, none of the production chains were valid after returning to Real World.
And in factory a Silica->Glass link was now an Oil->Glass link.
And even the Pre-defined Layout Plan are corrupted.
This is two of the Pre-defined Layout Plans currently existing in my Factory Layout Plan Library.

The first is weird as it suggests CPU is made from Silicon and an unknown porduct, and that something is then made from CPU and this unknown product.
it looks like it originally was Layout Plan for Notebook Computers, but now with 2 unassigned Purchasing Unit, and an extra link between the CPU unit and the purchase unit above.
The second looks like it is a Layout Plan for Cars, but now with two unassigned Purchase Units.
The players can't edit pre-defined plans, so it must be some errornous code that causes these weird changes
I found out that the Layout Plans are saved in C:\Users\%usernane%\Documents\My Games\Capitalism Lab\GAMESET\1STD.PLO, so I have zipped and attached that file.
And as we are talking Layout Plans:
I can see no reason for pre-defined and users defined plans being separated.
Some of the pre-defined plan are somewhat inefficient and probably rarely used, but they can't be removed.
Deleting the Category "Pre-defined Plans" Renaming "User-defined Plans" to "Complete Plans" or something similar and letting the pre-defined plans just be some predefined Complete Plans would make it possible for each player to only have Plans in their Library, that they actually use.
And lastly, why is not possible to set up a software producing unit.
When created they are basically just an ordinary manufacturing unit, that you can change any software product you want.
Again it is about efficiency. A software factory is initailly set up with 4 manufacturing units, but one manufacturing unit can actually cover the entire need for any software product, without even getting above 0% Utilization. even for small factories.
Based on that, a software producing unit at level 9, and 100% Utilization, would be able to cover at least 800 cities.
The only unit in a software factory is the sales units, and I have tried modifying a software factory to contain 2 purchase units, 2 production units and 5 sales units, and even though all sales units were close to 100% Utilization, the production units were still at 0%.
And I guess it would also be possible to allow saving a software layout plan.
Currently it is not possible, and the argument is that the software are unique from game to game.
That could be solved by saving a software unit as an unassigned unit, similar to purchasing units in wildcard plans.
The PLO-file: http://www.lerura.dk/CL/1STD.zip