When the code to centralize management of resources added a lock/unlock stage to texture access, the locks were not added with a try/finally paradigm to ensure that the textures were unlocked under all circumstances. As a result they only get unlocked if the render pass concludes normally.

Something needs to be done to ensure that the textures get unlocked during an abnormal termination of the render pass - either by using try/finally everywhere they are locked, or by forcibly unlocking all textures at the end of a render pass.