I created some custom buttons for my Opportunities tab. For some reason they're not working.

My "Send NY Invite" button is giving me this error:

Unable to Access Page

The value of the "template_id" parameter contains a character that is not allowed or the value exceeds the maximum allowed length. Remove the character from the parameter value or reduce the value length and resubmit. If the error still persists, report it to our Customer Support team. Provide the URL of the page you were requesting as well as any other related information. 

and my "Send Vegas Invite" button isn't recognizing the Contact ID and putting it in the "To" field of the email.

I compared both buttons with the working "Send LB Invite" button and it looks like it matches, so I'm not sure why it's not working.

Working LB button code:

/_ui/core/email/author/EmailAuthor? 
p2_lkid={!Opportunity.Primary_ContactId__c} 
&rtype=003 
&p3_lkid={!Opportunity.Id} 
&template_id=00Xd0000000XAm6 
&retURL={!Opportunity.Id}

Not working NY code that prompts the error mentioned above:

/_ui/core/email/author/EmailAuthor? 
p2_lkid={!Opportunity.Primary_ContactId__c} 
&rtype=003 
&p3_lkid={!Opportunity.Id} 
&template_id=000Xd0000000XB4j 
&retURL={!Opportunity.Id}

Not working Vegas code that doesn't recognize the Primary Contact:

/_ui/core/email/author/EmailAuthor? 
p2_lkid={!Opportunity.Primary_ContactId__c} 
&rtype=003 
&p3_lkid={!Opportunity.Id} 
&template_id=00Xd0000000XG9s 
&retURL={!Opportunity.Id}

Hi,

I would like the data in the first line of the address field to look like 

10 Downing Street.

Is there a way to capitalise the initials using formula?

Many thanks,