Q:

I'm not able to post a question

I get the following message when trying to post on Stack Overflow:

Your question couldn't be submitted. Please see the error above.

But I see no error message specifying the error.

A:

The tag you want to use (wia-2.0) does not exists (yet?) and you need 1500 rep to be able to create a tag. That's why you get an error. I guess the error message should says something like that.
Instead, you should ask your question with the tag wia and specified, inside your question, that you use the 2.0 version.

A:

The error message is probably to the right rather than "above" and you are mistaking it for an advertisement. Some recent layout changes to errors on form validation are being drawn as a solid filled flyout to the right of the item where the validation issue is located. This makes them appear to be in the sidebar and people's eyes gloss over them.
The issue has been previously reported and acknowledged by the SE team. They should be fixing it sometime in the next 6-8 weeks.

