Instagram allows up to 10 different photos (or videos) to be uploaded in a single post, however, some users reported the application crashing when trying to upload more than five at a time. This bug has been present for some time and seems to affect even the newest devices.
There is currently no clear, potential solution to this problem, however, there are some steps that can be taken to stop it from happening. Most of these potential solutions are relating to the available storage and memory of your device. Your first step should be to completely close any running applications, clear your Instagram application cache and see if the problem persists. If the app is still crashing, then you’ll need to restart your device as well. As a last-ditch attempt, you might need to reinstall the application, but make sure there is adequate storage available.