You may run into a problem posting photos to Instagram or even leaving comments and liking photos. If you’ve been on a spree of uploading, liking and commenting, you may have bumped into an anti-spam limit that is meant to protect the community.
Check your signal to see if you can do other things online. If you can access other websites and apps then you may need to continue troubleshooting Instagram. If you have issues with other services, or they are slow, you can try connecting to WiFi or turning airplane mode on and off.
The next thing to do is see if you can upload from a second Instagram account. If you don’t have one of those you should try to sign into Instagram using a browser on your phone or computer and then change something small in your bio. This can fix the problem and allow you to start posting to Instagram again.
If Instagram crashes when you try to upload a photo, you should restart your phone to see if that solves the problem. If all else fails, you can contact Instagram for more help and see if there is a problem with your account.