I've been using Chimera 1.5.3 under Linux (Ubuntu 12.04, 64-bit) without problems; that version I had installed as root, and is 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
   Current serial number in output stream:  2813