When W and H values are linked, it is still possible to make [layer width or height] <1 [which results in broken document state]. Try with a text box layer W=200 and H=600. Link the value, then set H=1. This will result in the W to be less than 1 and reproduce the original issue. In fact, this can be an issue with vector layers also. It is possible to set to the value smaller than 0.1.
As reported by @ktaki in #3717:
When W and H values are linked, it is still possible to make [layer width or height] <1 [which results in broken document state]. Try with a text box layer W=200 and H=600. Link the value, then set H=1. This will result in the W to be less than 1 and reproduce the original issue. In fact, this can be an issue with vector layers also. It is possible to set to the value smaller than 0.1.