Update related module entry Zoho Flow not working with custom module ?

Update related module entry Zoho Flow not working with custom module ?

Hi everyone. I am facing an issue here on Zoho Flow. 
Basically what I am doing is checking when a module entry is being filled in with an Event ID. Event is a custom module that I created. If the field is being filled in I fetch the contact with its ID ad the Event with also it's ID. 
Then I want to update the related module Event with the contact information so that in both my module Contact or Event I know who attended the event. 
The Flow is supposed to be really easy and basic as I just fetch for contact and event and then update the related module entry. However the "Update related module entry" Action in Flow doesn't seems to work. I always get the error "Zoho CRM says \"the module name given seems to be invalid\"" but my Module API names are defenitly correct. 

Any help on this ?