I'm a student from Pakistan I was willing to attend GopherCon UK 2019 I had purchased a ticket. I had provided all of the required documents. My visa was refused due to a lack of financial evidence. I had Provided the following Documents:
ID ( Passport ID Card) Cover Letter. Bonafide Letter from University. Invitation letter from the Conference. Paid Ticket of the conference Past educational Proofs Booking of Return Flight
Mother's Documents include Declaration Letter, Bank Certificate, Proof of current property ownership, Proof of Relation, Husband's Death Certificate, Insurance Letter
Sponsor(UK), Invitation Letter, Passport, Bank Statements, PayRols, p60, Accommodation Proof, PaySlips of Last 6 Months
and a few other documents to support my case.