It is the largest problem and it is all problems with Swedish society.
It create more and more of all problems.
The only "problem" I can think of which isn't due to immigration is that people live longer, have had fewer children and as such that the share of the population which are older and hence wouldn't work if it was the normal Swedish society would had grown larger making them more of a burden of society.
My solution there would had been to let each generation or individual save money for their own pension instead of relying on future tax payers.
But yeah. That isn't directly connected to immigration and is a "problem" of it's own. However Swedish refugee immigration isn't a solution to that problem regardless because of how poorly qualified they are and how long it take to get them into jobs and how many of those jobs are subsidized jobs. For the refugees to contribute positively to that AT THIS TIME they would have to job and pay in taxes and not collect welfare. However refugees will get old too and will need to be supported at that age they as-well and as such over their life-time they will just weight the Swedish system down even more.
Some news tabloid just recently bragged about how many more of the immigrants got a job here than in Denmark and Norway and so on it was just that 4/5 of those jobs was subsidized so
There's also things like they being over-represented in heavy criminality with 3-4 times, some of them in rape cases 20+ times but by now I assume it's even higher but the political establishment doesn't want new up to date numbers of that for some reason