Hello Thrygve ... Meanwhile 466 jumped out of the magicians hat, fixed quite a bit of issues i had, especially regarding bar count changes it seems (like a 2/4 measure inserted in a 4/4 song), and VST problems with some plugins I think also. But i still find some RTs missing a bar, especially the soloist type versions.

I take it your on Windows, not MAC.

Hardware: If you use Windows 10 and an external USB drive like the USB 3.0 WD one your Audiophile came with, problems are often USB related. First of all use a quality cable, but the one from WD seems adequate when tested for speed. Then look at the USB port you use. I had and have problems regarding the chip brand and drivers with an RME audio interface. Found that ASmedia chips with USB 3.0 and 3.1 suck, and NEC (Renessas) work far better regarding hiccups, dropouts and distortion. Un plugging and re plugging (wait at least 30 seconds, using a power switch to 'on-off' is better) an USB drive or -audio interface often fixes realtime issues too since the drivers are loaded again.

If you use a laptop in might be an idea, as you cannot plugin some other brand PCIe USB 3.0 card, to remove the USB drivers (uninstall them all, also the "HUB" ones, in Device Manager) let Windows re install them again. Further more: NVDIA graphics can cause problems with USB Audio. Switch off acceleration and other gamers' software gizmos, or try to find the LATEST barebone drivers, UNINSTALL the old ones, preferably use a cleanup tool like ATI has at their site). I have an ATI Radeon, but found i had to do the same, and bingo, my "realtime" USB performance was a lot better. Also find the latest Chipset drivers and mainboard BIOS (also for a stand alone PC).

Software: Some VST plugins can cause en extensive load on processing power also due not so efficient programming maybe. F.I. Yamaha Vocaloid is almost unusable because of this on Windows 10 64bit in my situation.

I had a bought Bitdefender 2017 Total Security causing serious problems with USB and my RME USB audio interface, and think they were firewall related. I now bought 360 TS and use it with Zonealarm free (firewall only). You can easily mark a whole (USB) drive as being safe with no need to be scanned. All virus killers seem to think that any external USB drive is a prime suspect for computer crimes aboard, courtesy of Kim Il Jung (oops, no politics). F