Observed with JCloisterZone 3.1.1 in 2 player play, one Windows machine, one Ubuntu.
Expansions in use: Inns & Cathedrals, Abbey and Mayor, Mage & Witch
This issue occurs when it is player A's turn to place a meeple or an abbey tile. Player A will see the skip button as well as the meeple or abbey tile whereas player B does not see the skip button as it is not his / her turn. If player B presses space or enter (keyboard equivalent of pressing skip), then the meeple or abbey tile placement is skipped giving player A no chance to place their piece.
I'd say this is a high priority bug as it will cause player conflict. I found it because my playing partner accidentally skipped my abbey placement but it seems that the issue is wider.
Please contact me if further explanation is required.
Khalid
Linkback: https://www.carcassonnecentral.com/community/index.php?topic=2116.0