A customer wrote in with a strange issue - if she rebooted her mac (10.8.5) and had iScreensaver set to run within 1-2 minutes, she’d get errors that said:
“Runtime Error : RuntimeThread.cpp:2615”
This error indicates that the screensaver was unable to allocate a temporary file.
After some back & forth, we analyzed the third-party software that she had installed, looking for problematic ones.
We came up with a list of possibilities, and she began removing them one-by-one.
As it happened, Intego Backup Assistant seemed to be the problem one.
This product is from LaCie http://www.lacie.com/products/product.htm?id=10323
Removing it seemed to fix the problem, allowing screensavers built with iScreensaver Designer 4.5.0.388 to work normally.