Custom number format works in pc, not on colleague's PC - error message inside

[theexcelcrowd]

I'm trying to use a custom number format to switch between K and M, depending on the number of digits.
Here's the format I have:
[>=1000000] #.0,," M";[>=1000] 0.0, " K";0
When I use this on my PC, it applies the formatting correctly.
When my colleague tries the same formatting, the below error message is shown:
"Excel cannot use the format format you typed. Try using one of the built-in number formats".

Any help with this.
Thanks.

 

[RoryA]

Does your colleague use the same regional settings as you? Does your workbook work on his PC?

 

[theexcelcrowd]

Does your colleague use the same regional settings as you? Does your workbook work on his PC?

Not sure about settings but the workbook opened in my colleague's pc. What should I be checking in regional settings?

 

[RoryA]

If it opens correctly on that pc, check the number format of the cell with it open and see how it differs from what you entered.

 

[theexcelcrowd]

If it opens correctly on that pc, check the number format of the cell with it open and see how it differs from what you entered.

We tried that as the first step by pasting the c.n.format copied from my pc. That's when the error showed up. In today's test, I tried emailing the file [with format] and it shows correctly.

 

[RoryA]

What I'm saying is to open the workbook on the other PC and see what the custom number format code looks like there. Presumably it doesn't look the same as it did on your PC.