Schedugram throws errors sometimes. Unfortunately that's part and parcel with how the service has to work.
Below are some of our top tips that all users should check to minimise the errors you might get.
Check the password is correct
If you get password-related errors a lot, see this article.
Check that you can login yourself, on your own device
Sometimes errors are caused by screens from Instagram asking you to follow more people, or to validate a login (sometimes by us). Make sure you can login using the username and password you have on your account.
Validate your email address and telephone number (add them if you don't have them)
Instagram prefers users to have a validated email address and phone number on each account. This is a good idea anyway, because it provides you a higher level of security in the event your account is compromised. Add them to your profile and make sure they're validated.
Post less often
Posting very frequently has three problems: you're more likely to run into problems if the jobs "run into" each other, Instagram may flag your account as spam or rate-limit it if you do it consistently over a long period (!), and perhaps most importantly, you're likely to annoy your followers. Posting 1-5 times a day is best, with the images spread out over the day. Of course, there are always exceptions and times that warrant more frequent posts, but fewer posts are typically more successful. We recommend having at least an hour in between posts.
Post shorter or less complex captions
Your 1,000 word caption is unlikely to be read, and is also likely to annoy your followers (see above). Instagram's character limit seems to vary a little bit between accounts, but it's always a good rule of thumb not to go crazy.
Don't go insane on the #hashtagOverload
Hashtags are great to get your content out there and discovered by new Instagram users. They can also be spammy -- just because people like to browse #PicOfTheDay doesn't mean that every single photo you post is a "pic of the day". Make sure your hashtags are relevant and keep them to a reasonable number -- Instagram has a hard limit of 30 hashtags per post, but that doesn't mean you should use 30 in every single post.
Don't post links in your captions
This one is an Instagram issue -- sometimes the service takes exception to users who post URLs in their captions. Keep the links to a minimum and only "as required", rather than on every single post. We recommend having your website link in your profile bio, which means users can click on it, rather than in captions. If you do post links in the caption, make sure they're easy to type -- use a link shortening service like bit.ly and make sure there isn't an awkward mix of capitals and lowercase letters.
Check the format of your uploaded images
If you get blurry images or they fail a lot, you could have an image format problem. We recommend making sure images are 640 x 640 pixels (slightly larger is okay, but over 1000x1000 is overkill) and in JPEG format, as this is what Instagram likes best. Blurry or pixelated images are usually because you've uploaded a picture smaller than 640px.