Fee exceeds maximum configured by user

[liorko87]

I created an altcoin for research purposes.
When I'm trying to send a transaction I'm receiving this error:

Code:

Fee exceeds maximum configured by user (e.g. -maxtxfee, maxfeerate)

I tried to set a fee as the second argument but the problem still exists.
When I debugged it, I can see that the max_tx_fee is calculated from the vsize of the transaction.

How can I overcome this error?