Recently had an issue when processing dimensions in BPC. The process would complete without errors, but the OK button was disabled. The only way to exit was killing the application. Turns out the recycle limit on the DefaultAppPool was causing this.
Even though minimum memory was set to 60% before the app pool would recycle, and even though the memory on the server never got close to 60%, the process wouldn’t finish. I turned off recycling based on memory usage and processing completed fine.