Vídeo bug

I cannot see what type of codec you are trying to edit,but, I CAN see that your storage drive situation is poor, and possibly is causing a " bottleneck" depending on how you are using them. You need to have faster drive volumes, especially where your media is placed.

1. the Kingston SSD is not really a good boot drive.....the 128GB versions all have a much slower write speed which can affect overall system performance . Better to have a Samsung 850 Pro which has 3D MLC memory and is well over 500MB/sec. read and write. 256GB is minimum size as the 128GB versions are slower. Your boot drive should ONLY have the OS, programs , and Windows page file on it.  If you had the Samsung SSD, you COULD put the "media cache" and "cache" files on it without any performance penalty and for easy deleting of those files.

2. You need a FASTER "project drive". Either get another SSD ,or, RAID 0 the 2 Seagate HDDs off the motherboard to form a 2 TB volume which would run much faster. Of course, you would buy an "enterprise level" 2TB HDD to BACK UP that RAID for data safety. Here's one at new Egg for $60 :

Seagate Constellation ES ST32000644NS 2TB 7200 RPM 64MB Cache SATA 3.0Gb/s 3.5" Enterprise Internal Hard Drive Bare Driv…

PPro and After Effects will  place the highest demands on your system, so :

1. Make sure your video driver is current and comes from NVidia

2. Make sure your OS is current and fully updated

3. make sure that " indexing" is turned OFF on all your drives

4. Try Overclocking the CPU a little higher, if you have a good cooler

5. Use the free utility " MSI Afterburner", or similar, to gain performance by increasing the "memory clock" speed on your GPU

6. Test the speed of all your current drives....especially the external drive which may be the slowest. Make sure they are defragmented and less than half full, if possible, or drive performance will be low.

Have you tried updating or rolling back your video driver?