I've been using Chimera 1.5.3 under Linux (Ubuntu 12.04, 64-bit) without problems; that version I had installedas root, andis owned by root. Just now I updated to version 1.8, which, initially, I also installed as root. But trying to run it (as non-root) gave me fairly opaque error messages(copied below). On a hunch that it was a matter of privilege, I tried running with `sudo` -- which works fine. Since it was not obvious where the problem lay, I cleaned out the installation, and installed anew as a normal user (me). Accordingly, the whole installation directory tree is owned by me. But still I cannot run it (same errors) as me, but only with `sudo`. Same user, same start directory, apparently the same Python (2.7) as works with v. 1.5.3. I'm totally flummoxed! Can't imagine where the privilege hang-up is. Any hints where I should look? Thanks, Bob Wohlhueter *****************************C-shell output******************* chimera X Error of failed request: BadRequest (invalid request code or no such operation) Major opcode of failed request: 128 (GLX) Minor opcode of failed request: 198 () Serial number of failed request: 2813 Currentserial number in output stream: 2813