Can not highlight text when editing.

Hi,

I have the same problem and found out yesterday that this is a known type issue: "When using the Type Tool, the I-beam pointer and the text selection are not visible when typing in CMYK, Lab, Grayscale documents."  https://helpx.adobe.com/photoshop/kb/known-issues.html#Type

My workaround is that I created a simple file with text in RGB color mode that I keep on my desktop and I use that to launch Photoshop first. If I launch RGB first, then the I-beam behaves in other CMYK files until I quit Photoshop again. Hope that helps. (And of course I hope that they figure out a way to fix this issue, this is somewhat ridiculous!!)

As already suggested, try to reset tool if that does not work then try to reset preferences.

Hi

What exact version of Photoshop and operating system do you have, not seeing any issues here on Windows 10 using Photoshop 20.0.6

Try resetting the Type Tool