Undefined index: field_id_60

Did you have any luck with this? I’m running into the same issue only there’s no relationship field at play. I have a grid field within a fluid field that seems to be the culprit.

I’m getting something similar now too, as well as this PHP error mesage:

Cannot modify header information - headers already sent by (output started at ee/legacy/core/Exceptions.php:120)

Anyone of you managed to sort this? I read elsewhere that the server’s ICU version may be at fault.

Sorry mcfarlando and Pigtail, I never did. In fact, shortly after running into it I abandoned EE as the solution for my shop. Absolutely not a real solution for most projects.

I don’t know what ICU is. My EE environment was built on an AWS instance using PHP 7.3 I believe.

I’m willing to bet the rebuilding your structure will correct the problem, but that’s also not a realistic solution. In my case, my use of Fluid and Relationships was so complex that I think EE couldn’t keep up with it anymore.

I’m sorry I don’t have the answer.

So i had this issue today aswell, don’t know if it awsers the question but i got it to go away for me at least.

I have a grid fieldtype that has a relationship field setup. without any entries that use it yet and i get the error:

Notice
Undefined index: field_id_66
ee/legacy/libraries/channel_entries_parser/components/Custom_field.php, line 97

Severity: E_NOTICE
Warning
Cannot modify header information - headers already sent by (output started at ee/legacy/core/Exceptions.php:120)
ee/ExpressionEngine/Boot/boot.common.php, line 477

Severity: E_WARNING

For me the solution was that i used double quote to check if the fieldtype was filled like so:

{if "{grid_fieldtype}"} do stuff.. {/if}

When i removed the double quotes and brackets the warning disappeared

{if grid_fieldtype} do stuff.. {/if}

Hope this helps

Just in case someone is having a similar problem, I was getting those same type of error messages and it did seem to be the issue of having a conditional using a related field grid field. Interestingly, just the opposite from the above worked for me. I initially had

{if relationship_field:grid_field:row}

and what got rid of the error messages was instead using this:

{if "{relationship_field:grid_field:row}" != ""}

I hope that’s of use to someone….