Others point to good things to try out.

Here's also a good resource for anyone to use to trouble-shoot audio issues further..

Glitch Free - by Brad from Cantabile software

Has well organized and easy to understand info and solutions (like settings from CPU or page file, other background processes etc.. and so many things - a lot of those maybe not so necessary on newer powerful machines).

Always a good publication to share around.

Mismatched sample rate glitches is not a thing particular to Pianoteq - but I've encountered a mismatch glitch or two.

If you think it's this.. maybe in the DAW delete (or refresh) plugin cache, and set the DAW to re-scan plugins on startup.. that way, you may encounter less 'old' data getting in the way of normal functioning.

I know some people who never seem to have issues - but I'm someone who has - so I understand when some stupidly simple nonsense can take way longer than normal to find and fix.

Good luck Albert! Let us know how you got on if you get time.

Cheers all.

Be sure that the sample rate is the same in Pianoteq (Options/Perf) as in Reaper (Ctrl+P Audio/Device)

I'm not sure if a mismatch would be a problem. I've recorded loads of music in Reaper with Pianoteq set at 48khz but my project set at 96khz. No problems encountered ever, nor would I expect any. Even if Pianoteq were set to 96khz and my Reaper project was set at 48khz I'm not sure it would be an issue: I assumed the sampling rate for Pianoteq is internal to the plugin.

Be sure that the sample rate is the same in Pianoteq (Options/Perf) as in Reaper (Ctrl+P Audio/Device)
I had this problem once.

This!

Hallo, when I use Pianoteq stand-alone it works fine. But when I use it as a plugin in reaper, I get clicks and tics when I record midi tracks with pianoteq and also when I playback the track, it seems even to influence the later recorded vocals. I tried some settings but so far nothing works.
Help would be appreciated.
I have a laptop pc with an i7 processor, in stand-alone mode I have around 30-35% CPU usage.

I had the same problems when using VCV Rack with Reaper on Windows, and I found that it can help to set your power/performance profile to High performance.

This is a common problem with DAWs and plugins on Windows, even Ableton mentions it in their docs:
https://help.ableton.com/hc/en-us/artic...n-Windows-

Hope this helps!

What sample rate and block size?
Try 48khz.
96-192khz  will dramatically increase CPU hit.

Extra FX?
ASIO or WASAPI or something else?

No problems here in Reaper win x64.
What operating system are you using?

Reaper was updated today FWIW.

Hallo, when I use Pianoteq stand-alone it works fine. But when I use it as a plugin in reaper, I get clicks and tics when I record midi tracks with pianoteq and also when I playback the track, it seems even to influence the later recorded vocals. I tried some settings but so far nothing works.
Help would be appreciated.
I have a laptop pc with an i7 processor, in stand-alone mode I have around 30-35% CPU usage.

maybe your sample block/buffer size is too low?

try setting it at 256 samples, then 512 if the problem persists.