I've moved your post to a new thread to keep it separate from Vasily Iakovlev's problems in this thread.
Vasily's 'Pages' layout problem was caused by old or corrupt versions of the '/showkase/admin/css/all.css' and '/showkase/admin/css/bootstrap.min.css' files.
Replacing them with the stock versions from Showkase v1.6.1 resolved the problem.
i am getting the same error as the OP trying to upgrade from v1.3.4 to v1.6.1 (unable to publish the site).
Vasily was not actually unable to publish the site. There was just a warning regarding the PHP function set_time_limit() being disabled. Clicking through this message (it was just a warning, not an error) published the site successfully.
If you are seeing the same warning "Warning: set_time_limit() has been disabled for security reasons", then this is due to the set_time_limit() function being disabled in your PHP configuration settings.
As I mentioned in Vasily's thread, this is just a warning (not an error).
Showkase (since v1.3.4), makes use of set_time_limit() and if this PHP function has been disabled on your server, then there is nothing that can be done within Showkase to enable it.
However, unless your site is very large (and Showkase needs more than the default time limit to process everything), it may never actually become a problem. Just clicking through the warning message should publish your site fine.
If you do have a large site and you are unable to publish it successfully because of set_time_limit() being disabled, then I am surprised that reverting to v1.3.4 helps. (Versions prior to v1.3.4 do not use set_time_limit() so the default time limit will be used, just like in v1.6.1 with set_time_limit() disabled.)
In any case, if you would like remove the set_time_limit() warning, you'll need to enable this function in your PHP configuration settings. If you do not have access to change your PHP settings yourself, your web host should hopefully be able to help you out.
If you are getting any different messages when you try to publish your site (whether they are notices, warnings or errors), please let me know and I'll try to help further.
Thank you.