Your Windows OS is not current on Windows updates.

More details below:

When install Sage300, the IIS config file will add Sage 300 web site settings from Sage300 web.config. If windows OS version not support new SameSite, it doesn’t update IIS config file correctly as Sage300 web.config has:

<authentication>

<forms cookieSameSite="None" />

</authentication>

For windows 10, OS build must be OS 1803, Build 17134.1184 And after See: https://support.microsoft.com/en-ca/help/4530717/windows-10-update-kb4530717

For windows Server:

Microsoft require the windows update to support new SameSite cookie policies by default for release 80 of Google Chrome

Windows Server updates:

These updates already applied to

Windows 10, version 1809, all editions, Windows Server version 1809, Windows Server 2019, all editions