First Minister Nicola Sturgeon gave an update to MSPs at the Scottish Parliament on Tuesday.
One MSP suggested the Scottish Licensed Trade Association was ‘crying wolf’ at a Holyrood committee.
The Night Time Industries Association said problems with the app led to ‘chaos and confusion’.
No fans will be asked to provide proof of vaccine when Aberdeen host Celtic on Sunday,
The scheme is due to go live on October 1 for large events and nightclubs.
The deputy first minister said measures to check vaccine passports at large events would be ‘proportionate’.
The Music Venue Trust (MVT) called on the Scottish Government to actively engage with the sector.
MSPs are due to vote on Nicola Sturgeon’s vaccine certification proposals next week.
First Minister announced that vaccine passports will be needed for people attending large-scale events in Scotland.
Chief medical officer says service will provide people with a record of their vaccine status for international travel.