Hello,
The first thing to try is to get a newer version of Chimera.  I tried SMILES fetch in a recent version just now and it worked fine. 

If you get the newest release of Chimera and it still doesn't work in that version, then report the problem using Chimera menu: Help... Report a Bug and fill in the information including your email address if you would like a response.

I hope this helps,
Elaine
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Elaine C. Meng, Ph.D.                       
UCSF Chimera(X) team
Department of Pharmaceutical Chemistry
University of California, San Francisco

> On May 16, 2023, at 5:38 PM, Athithi Prakash via Chimera-users <chimera-users@cgl.ucsf.edu> wrote:
>
> Hello, I have been trying for a while to build the structure using the SMILES ID, and every time, this error pops up and I am not sure what to do.
> <Screenshot (10).png>