Response error -> Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 1 path $

import com.google.gson.annotations.Expose;
import com.google.gson.annotations.SerializedName;
import com.orm.SugarRecord;

public class Repayment extends SugarRecord {

    @SerializedName("repaymentId")
    @Expose
    private Integer repaymentId;
    @SerializedName("loanId")
    @Expose
    private String loanId;
    @SerializedName("borrowerId")
    @Expose
    private String borrowerId;
    @SerializedName("amount_paid")
    @Expose
    private String amountPaid;
    @SerializedName("balanceOfLoan")
    @Expose
    private String balanceOfLoan;
    @SerializedName("created_at")
    @Expose
    private String createdAt;
    @SerializedName("updated_at")
    @Expose
    private String updatedAt;

    public Integer getRepaymentId() {
        return repaymentId;
    }

    public void setId(Integer repaymentId) {
        this.repaymentId = repaymentId;
    }

    public String getLoanId() {
        return loanId;
    }

    public void setLoanId(String loanId) {
        this.loanId = loanId;
    }

    public String getBorrowerId() {
        return borrowerId;
    }

    public void setBorrowerId(String borrowerId) {
        this.borrowerId = borrowerId;
    }

    public String getAmountPaid() {
        return amountPaid;
    }

    public void setAmountPaid(String amountPaid) {
        this.amountPaid = amountPaid;
    }

    public String getBalanceOfLoan() {
        return balanceOfLoan;
    }

    public void setBalanceOfLoan(String balanceOfLoan) {
        this.balanceOfLoan = balanceOfLoan;
    }

    public String getCreatedAt() {
        return createdAt;
    }

    public void setCreatedAt(String createdAt) {
        this.createdAt = createdAt;
    }

    public String getUpdatedAt() {
        return updatedAt;
    }

    public void setUpdatedAt(String updatedAt) {
        this.updatedAt = updatedAt;
    }
}

@GET("loan_balance")
Call<Repayment> getCurrentLoanBalance();

public void getBalance(){

    APIInterface apiInterface = APIClient.getClient().create(APIInterface.class);
    Call<Repayment> call = apiInterface.getCurrentLoanBalance();
    call.enqueue(new Callback<Repayment>() {
        @Override
        public void onResponse(Call<Repayment> call, Response<Repayment> response) {
            try {
                Utils.log("Response -> " + response.message());
                Repayment repayment = response.body();
                aQuery.id(R.id.loan_limit).text(repayment.getBalanceOfLoan());

            } catch (Exception e){
                Utils.log("Error retrieving repayment -> " + e.getMessage());
            }
        }

        @Override
        public void onFailure(Call<Repayment> call, Throwable t) {
            Utils.log("Response error -> " + t.getMessage());
        }
    });
}

implementation 'com.google.code.gson:gson:2.8.5'
    implementation 'com.squareup.okhttp:okhttp:1.3.0'
    implementation 'com.squareup.retrofit2:retrofit:2.3.0'
    implementation 'com.squareup.retrofit2:converter-gson:2.1.0'