Why have my data validation dropdown boxes have stopped working?

[Kelvin Stott]

I have some files with data validation in dropdown lists, and these have been working fine for some time, but suddenly none of the dropdown boxes appear for any of the cells. I've checked all the data validation settings, and even reset them, but still the dropdown menus don't appear in any of the cells. I suspect it's related to some global settings, but can't find where the problem is. Any ideas?

PS. The calculations are set as automatic, so it's not that.

Thanks for any help.

Kelvin

 

[VoG]

This may help http://www.contextures.com/xlDataVal08.html#ArrowsNotVisible

 

[Kelvin Stott]

Many thanks -- that was a helpful link and I found the answer.