Hello,

How did you make fields mandatory ? if from UI policy then make it mandatory from dictionary if made it mandatory from dictionary then use UI policy.

Also, for number field it should be of type Single line text and use regex validation method using below

https://community.servicenow.com/community?id=community_article&sys_id=ebcf2b6edbd7d0103daa1ea668961973

Try these two.

Please hit like and mark my response as correct if that helps

Regards

i made the fields mandatory from the catalog builder

and i used already the regex validation for a number

any idea why it is still not working?

The location item is what caused the error for me. I had Choice and Record reference and it did not like it... changing it to type = 'Reference' resolved the issue and it worked. 

1. "Reference" was not one of the choices in the simulator drop-down, only 'choice' [which did not work]

2. Go to 'Maintain Catalog' and select 'Consulting Practice', go down to the catalog items and select 'Workshop Setup', then go down to 'Variables' and select the 'Workshop location' [if you are getting the error you will be clicking on 'Choice', now change the 'Type' to reference.