Steps to reproduce:

1. Open attached project "791046.zip"
2. Open scene "repro"
3. In hierarchy, select "Canvas > Image" and change Image Type to Tiled
4. Notice that everything works as expected
5. Set Image Type back to Sliced
6. In project tab, select "slip_title" sprite and click Show in Explorer
7. Open sprite using external image editor and change its size to 63x10 (height and width is lowered by 10 pixels each)
8. In scene view, re-select Image and set Image Type to Tiled again
This time Memory starts to build up and computer freezes

Reproduced with: 5.2.4f1, 5.3.4p4, 5.4.0b16