Loading screen only covers up half the screen

Sometimes, when I open up a project, when the project is loading in the editor, the loading screen only covers up half the screen. Why?

because it's only a bug due to URL errors or too many tabs on your web or number amount of tabs is 0 divided by 0

how could your number of tabs be 0/0? and how would that affect the snap! tab?

sorry I mean because it's only a bug due to URL errors or too many tabs on your web or the number amount of tabs is 15^15^15^15^15^15^15^1000