Sometimes (twice so far) if I restart the game after a crash and then attack a new shard, it misses the Magicians Workshop in the build order. The building is listed as requirement for the next Tier buildings though.

This is especially painful, because you need it for any Tier2 spells.

At first you don't notice, because you will only use Tier1 spells for a while and try to stay alive in the beginning. Later you want to improve and wonder where that building is.

I am not 100% sure if some worlds are meant to not have that building but the Tier2 constructions are visible, because I need to restart the game and would need to start a complete new attack on a shard to get a the building back. Then I wonder if this might be a different shard...

Every time I attack a new shard now, the first I check is if the magicians workshop is in my list of available buildings...

More details, less words in what happened :)
You continue an old save on a shard.
Game crashes.
You continue the old save on a shard.
You finish that shard and start attack on a different one.
Magicians Workshop is not in the list of available buildings.
You close the game properly.
You start the game from the campaign save.
You start a new attack and the magicians workshop is in the list of available buildings.

//edit: missing foresters guild this time: http://i.imgur.com/OAZRnoL.jpg

//edit: after rebooting and restarting the game a couple of times, it is back :D