Error: Unable to update Template Variable

Error: Unable to update Template Variable

Hi - I have been using the following code for over 12 months 

User_Email=zoho.loginuserid;
crmContactMatches = zoho.crm.searchRecordsByPDC("Contacts","email",User_Email);
alert (crmContactMatches);
for each contact in crmContactMatches
{
accId=(contact.get("ACCOUNTID")).toLong();
accountResp = zoho.crm.getRecordById(("Accounts"),accId);
System=(accountResp).get(("Parent Account"));
siteResp=(accountResp).get(("Account Name"));
facilityResp=(accountResp).get(("Account Site"));
Site:ui.add(siteResp);
Facility:ui.add(facilityResp);
}

Today, i am now getting the following error;

Error details:
Error in executing On Add - On Load script. 
Error.
Error in executing Iterate List task. 
Error in executing Set Variable task. Unable to update template variable accId.
Error evaluating NUMERIC expression

Whats happening - any ideas?