Dialogue hangs when I try to increase capacity of a datastore

[flycast]

ESXi 6.5

I have a datastore that is 7.25Tb. The datastore has 4.11Gb free. IT is full. When I go to expand the capacity of the datastore by selecting it and choosing "Increase capacity" I never get anything to select. The dialog just looks like this and hangs there:

What could be the issue?

[sjesse]

What browser is this, I'd try a different one if possible.

[flycast]

Great idea. I was using Chrome. I tried Firefox and Edge. It does the same on all three.