small molecule properties show as question marks when viewing previous puzzle

[LociOiling]

When switching to a previous small molecule puzzle without restarting Foldit, the small molecule properties appear as question marks. Doing a "Copy SMILES" at this point gets you "???" in the clipboard. Thanks to @alcor29 for spotting the issue.

Switching back to the current puzzle shows normal small molecule properties again.

Oddly, when switching back and forth, the Small Molecule Properties panel remains open. Usually Foldit closes things even you'd like them to stay open. I also noticed that the Rama map stays open between puzzles.

To create this problem:

1. Open 2718 and display the small molecule properties, which appear normal
2. Open 2715, the small molecule properties are still displayed, but the values are all question marks
3. Switch back to 2718, and the small molecule properties are normal again

There's another version of this problem, where the small molecule properties look normal but are incorrect. In one case, the properties were wrong, and didn't change with edits to the ligand. I think that may happen when you have one puzzle open at expiration time, and then open the new one without restarting.

I haven't recreated this version of the problem yet. If you open a puzzle after expiration, the properties may appear normal. Then if you switch to the current puzzle, you'll get the question marks.

[rmoretti]

The panel has a memory of which residue is the ligand. When you change puzzles, that can change, and if the ligand isn't where it's expected you'll get those question marks. You should be able to close and reopen the panel to reset the ligand. – That's not ideal, though, so we'll look into fixing that.