Hi @a_v_a
It looks as the 'sameSite' [SameSite][1] cookie policy is the reason of these 'dialog instance not available' errors.
**Fix**
Set the sameSite cookie policy to 'lax' to allow links from remote websites to work with the same session in dialogs.
1. go to `[ivy-product]/webapps/ivy/META-INF/context.xml`
2. uncomment the 'cookie processor' definition line
3. set the `sameSiteCookies` attribute from `strict` to `lax`.
4. reboot the engine, errors will be gone.
![alt text][1]text][2]
**Scope**
This policy was introduced with 7.4. So 8.0.0 is affected as well, but will receive a fix with 8.0.1. This issue is tracked as bug XIVY-3476.
[1]: https://www.owasp.org/index.php/SameSite
[2]: https://answers.axonivy.com/upfiles/contextXml_laxSameSite.png
