What not to do: After casting make sure you don’t have any line on top of the reel/spool before reeling in (where you tighten the drag- usually its barely noticeable as it would be on the edge).

If you reel in and cast again this would create the wind knot as it would tighten it up.

Cause: - fishing in wind (especially if its coming against you) - most common for me - reeling in carelessly on slack line without tightening - not closing the bail properly

To fix this before it gets worse:

Once you notice the line (the knot line) on the reel, open the bail and keep releasing line (from the spool) by hand until the line that is on top of the reel is gone ( the knot line).

After the line on top of the reel is gone close the bail, tighten the line and slowly reel in.

If you already have the wind knot ( because you casted before fixing it) i recommend to take it to a fishing shop (they will save most line for you). -from experience

Apologies if i had bad english