I apologize for the late response, what you describe appears familiar to me but I could use some more information.

First of all, because you deleted the shipcore anchor, the design that was currently loaded also got deleted. As far as I can see, that's intended (but very dangerous to have) but could be considered as an unwanted mechanic. That should be reported in a separate task.

It appears that your shipyard got stuck, usually those problems get fixed by unloading the sector and loading it again, but this only works for designs.

I don't understand what you mean with partial loading though, once the design appears visually, it's fully loaded (but not always rendered). The loading bar being partially filled, is that the one in the shipyard where you can see the progress on construction? If so, did you initiate construction then either logged out or moved out of loading range, and came back later to see the shipyard sitting in that state?

http://phab.starma.de/T642 is where designs unload after restarting the server or unloading the sector it is in. Could be related to what you had.

http://phab.starma.de/T752 seems to be same issue you had but hard to tell.

-Feedback-

I have had this and related bugs as well; they are hard to reproduce on purpose but probably have something to do with server lag. Shipyards in multiplayer do have the tendency to not complete orders for certain things in some cases. This will result in unusable, corrupted designs if relogging does not fix the issue, as a user has to remove the shipyard core anchor to fix the issue while the design is stuck in an operation, which invariably seems to destroy designs.

In T762#28485, @Ithirahad wrote:

I have had this and related bugs as well; they are hard to reproduce on purpose but probably have something to do with server lag. Shipyards in multiplayer do have the tendency to not complete orders for certain things in some cases. This will result in unusable, corrupted designs if relogging does not fix the issue, as a user has to remove the shipyard core anchor to fix the issue while the design is stuck in an operation, which invariably seems to destroy designs.

Yeah, removing the ship core anchor also deletes the entity of the loaded design, it doesn't remove the design itself though so I think it's a bug. Or more like a safety mechanism that shouldn't trigger. I'll make a new report for that so we can split this task up if needed (it will most likely merge with T752 though)

Was unable to find that the removal of a shipyard's anchor also deleted the design from the database, but the partial loading of the design was that the bar got stuck at what seemed to be 75% loading. T752 seems to be similar, but loading/unloading of the sector didn't fix it, and it occurred at random, rather than after a server restart. Ithirahad explained it a bit better. Here's some (hopefully) better detailing:

The hologram appeared when I chose to load the ship design and it allowed entrance to attempt work, but denied me the capability to do so, stating that the ship was not fully loaded. Approximately 10 minutes passed and the loading bar did not move, all buttons were greyed out. Attempting to unload the sector did nothing, and anything short of removing the core anchor didn't unload the ship. The design meta item still was in the shipyard computer, but would not load, stating the design did not exist in the databases, giving the stated error.

I'm not sure how I got into this same state initially, but I stumbled into a way to get the 'entity for design not valid in database' error repeatedly.

I hit the problem described above (stuck at 75% loading), removing the core anchor got it unstuck but produced the error above when I tried to reload the design. Thankfully I had a blueprint of the same design - I was able to create the design from the blueprint, but I'd accidentally rotated the core anchor such that the ship wouldn't fit in the shipyard when I tried to load the design. When I attempt fix the problem with the anchor and attempt to load the design again, I get that entity not valid error again.

Creating from BP with the anchor in a suitable place, the shipyard shows full progress on the --CreateDesignFromBlueprint-- task but is stuck in that state similar to the original problem.

Don't know if any of that helps, but figured more data can't hurt. Let me know if there's something else I can try to help troubleshoot the problem.

We have a similar issue in our queue, if it also matches here:
any loaded design will get corrupted then the anchor is removed.

The core anchor removal corrupting the design is reported (an in queue). The loading issue really seems what T752 has but looks like it has multiple causes. I'll merge the 2 tasks together and hopefully we'll find something we can reproduce consistently.