expressions such as x(x+1) - error messages

[BillFoster]

Expressions in answers such as x(x+1) are not allowed whereas x*(x+1) is for valid reasons. However, the error message only says "Not a valid mathematical expression" and this could be the case of much confusion as to the untutored eye x(x+1) looks very mathematical! The error message needs to be more specific in this case.

[christianp]

I get this:

This is not a valid mathematical expression. Operation 'x' is not defined. Did you mean x*(...)?

That's enough, isn't it?

[BillFoster]

I do not get the message 'x' is not defined. Did you mean.....

[christianp]

Can you send me a screenshot?

[BillFoster]

Still only get the message

This is not a valid mathematical expression.

when I input a(b+c) instead of the expected a*(b+c)

[christianp]

And that's because I forgot to update the numbas installation on the server. Try now.

[BillFoster]

OK - better message.