Without seeing your code it’s hard to know what the issue might be, though based on this stack overflow thread it sounds like the error you are getting is related to a for loop. From what I can tell in the error message, your use of ipumsr::read_ipums_micro() should work (see this forum post on reading ipums data in R). A good way to troubleshoot problems with code is to google the error message you are getting; I’ve had good luck finding solutions to troublesome code this way.