I'm finding this is quite bad. I'm not sure if there would be a config setting in PHP8 for my NAS box that would help but the issue cascades through code and really kicks the tyres.
Whilst I'm finding it difficult to understand what is happening I'll try and describe what I think is going on.
I have a pretty simple site which has two templates.
A single column and a double column.
Double:

Single:

Both have a top menu. The double column template has a section that shows the possible child menu options as well as a recent docs part. In the middle is a chunk that shows the profile/logout buttons.
My home page works, which has a simple DocLister call to show child docs.
Another page, Tutorials, works as expect too (id: 119).
If I click the child page: EvoCMS (ID 138) I get this error!

The 119 if refers to is the parent ID.
I've tracked it down to a chunk I have which shows the Profile and Logout buttons.
<div id="wlpeUser">
<fieldset id="wlpeUserButtons">
<a class="button" href="[~103~]" title="profile">Profile</a>
[[if? &is=`[*Login*]:is:Logout` &then=`<a class="button btn btn-primary" href="[~[*id*]~]?logout">Logout</a>` &else=`<a class="button btn btn-primary" href="[~4~]">Login</a>` ]]
</fieldset>
</div>
removing the url placeholder removes the error!
<div id="wlpeUser">
<fieldset id="wlpeUserButtons">
<a class="button" href="[~103~]" title="profile">Profile</a>
[[if? &is=`[*Login*]:is:Logout` &then=`<a class="button btn btn-primary" href="?logout">Logout</a>` &else=`<a class="button btn btn-primary" href="[~4~]">Login</a>` ]]
</fieldset>
</div>
Basically, any chunk within a template or page the has [id] (or [+id+] with DocLister) throws an error!