Unable to build unit in campaign

i cant seem to continue my LOTV campaign, on the 2nd mission i can only build stalker, and on my 3rd mission i can only build zelots. after the 3rd mission, it reset me back to the first mission and i cant proceed any futher. When i try master archives the ability wont work and i cant build any unit from my buildings.

I believe you are talking about Legacy of the Void (main plot about Artanis), not Whispers of Oblivion (LotV prologue with Zeratul).

Do you have buttons for unit production (with picture of zealots, stalkers)?

Are they coloured or grey? [Stalker needs Cybernetic Core to be available for production, however, Zealot should be always available from Gate]
Are you using mouse or shortcuts for production?

What do you mean by “after 3rd mission it resets me back to first mission”? You are unable to choose destination to Shakuras / Korhal? Does the game crash? Are you thrown back to the campaign choose menu?

I just played easy on NA and had no mentioned problems. Could you provide some screenshots showing mentioned errors?

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