Problem with Channel form throwing php errors

Full License of EE 2.7.1 I am using the channel form syntax pasted from the EE docs with out-of the box field types and I am get several PHP errors. The install was an upgrade from EE-core. I’ve used saefcracker and channelform on many installs without difficulty. Not sure what is up here. The errors get from using only the title field for input are here:

I get two of this error:

A PHP Error was encountered Severity: Notice Message: Use of undefined constant ‘1’ - assumed ‘‘1’’ Filename: config/config.php

and one of these:

Severity: Warning Message: Cannot modify header information - headers already sent by (output started at /homepages/17/d377560511/htdocs/Seed-Balls/system/codeigniter/system/core/Exceptions.php:170) Filename: core/Common.php

Any ideas?

Here’s what gives me the errors:

{exp:channel:form channel="tasks" return="tasks" entry_id="{segment_3}"}
<h3>Title</h3>
<input type="text" name="title" id="title" value="{title}" size="50" maxlength="100" >
<input type="submit" value="Submit">
{/exp:channel:form}