They are interchangeable in this context.
'slik', 'sånt' and 'sånn' are closer to 'this way or 'like this'.
'slikt' and 'sånt' are closer to 'things like this'.
*this answer has been edited.
Ah, but 'slikt' and 'slik' have different uses :)
Norwegian, the simple language™
How will this phrase be in plural? I originally speak Spanish and we say that kind of thingS (where "that" refers to the situation we are talking about and "kind of things" to the universe of situations where "that" fits)
You could rephrase it as "Slike ting skjer ofte", but "slikt" covers the plural meaning as well.
Slikt skjer - Non native English speakers may be amused by English phrase for 'That kind of thing happens' -> '❤❤❤❤ happens!'