Basically you can't put too much text at once without any spaces, as it messes up the page layout. Doesn't have to be a link but links are quite a common cause. We did have a separate field to put a website at one point, but it's a target for spammers so I removed it.
You can try removing the part at the front (e.g. http://www.
) and just start form the domain name, maybe that will be enough. Depending on the link there may be extra junk, for example in the instagram link you posted above the ?igshid=ehbsf4u1cjop
does nothing, you could put instagram.com/p/CHJlCA3Ayxi/
(just an example, I know that's not the link you were trying to add).
Otherwise, find a URL shortener and use that.