Contact Importing from SF - Lead Source field error


I’ve been trying to import contacts from SalesForce CSV to our SuiteCRM system but keep getting an error saying:

“Value not in dropDown list. Allowed values are: ,Advertisement,Facebook,Partner,Public Relations,Seminar - Internal,Trade Show,Twitter,Walk-In,Web,Word of mouth,“Lead Source:(lead_source)”,Flier,6”

Yes, I understand that in order to easily get rid of this error is to add ‘Flier’ value into the dropdown list dom but unfortunately, I found out that we have lots of various values that is too tiring to add into the list. We have 50 thousand list of contacts. I look into Saleforce and found out that LeadSource Data Type is ‘Picklist’ and I cannot find equivalent value on SuiteCRM. How can I fix this issue?

Thank you in advance!