Problems - Mixing in Logic Pro X

In doing the mixing and recording part of the third song "Confused" I am facing several problems.

I normally use Logic pro x as the DAW for my creation. It was totally fine before except sometime it would have a slow response. But when I tried to record the chorus part of this song, the software first got a delay on the monitoring of the mic input which I found it totally annoying and disturbing so I changed to use nuendo for recording the vocal. And It was totally fine for the same setup of mic in nuendo. After I recorded the vocal , I put the audio file back into the logic pro x mixing file. And I started doing the sound track editing and adding different effects and reverb . And then I starts to find out that the file can't run smoothly start from bar 12. It lags and stop at around bar 12 with an error message appears.

As shown above, every time I try to run the file it lags and stops. But If I skip Bar12-13 and start playing the file from bar 13, the reminding file runs perfectly. So I didn't treat this as a serious problem as I can still listen to the whole song.

When It comes to the exporting part, problems appears. In Logic pro X, we use bounce to output the mix-down. Whenever I try to bounce the whole mix-down out, It stuck in bar 12-13 and then it automatically stops the bouncing process which means that I can't even output the mix-down.

As the error massage said the system is overloaded, so I tried to turn of some effect inserts (eg. Delay, Tape Delay) but nothing change after I did this. Therefore, I muted the instrument that starts playing at exactly bar 12. In this time,the song could play through var 12-13 smoothly, but it stopped at bar 14 and the error message shown up again.

It would be a huge problem if it is because of the file is damaged, cause I don't have more time for redoing a song. I kept dealing with this problem in the project room 1 in CMC til 930pm, but I haven't got any progress so far. Therefore I decided to send an email to my adviser Charles and keep up with the problem tomorrow.