[SOLVED] 6.1.1 Error creating any new item

Hello,

I'm getting this error: ERROR: An error occurred on [date] at [time], every time I try to add a new item, regardless the topic (users, projects, documents etc).
When opening the log file, the error message is "A non well formed numeric value encountered".

This is a brand new installation and no errors / warnings were found during setup. I've kept the default english localization.
The site runs on a Mac, using MAMP (zendengine) server and a standard MySql db server.

Any hint?

Thank you

This is the detailed error when trying to see the details of any item
ERROR : A non well formed numeric value encountered
in objectDetail.php
at line 526

and there is another similar error (regarding formatting) when trying to add a new project
ERROR : A non-numeric value encountered
in ProjectPlanningElementMain.php
at line 207

I'm using Safari on a MacOS Sierra; Projector version 6.1.1., MAMP version 4.1.1.; MySQL 5.6.35, PHP 7.1.1.

Please le tae know if you need the entire phpinfo page.
By the way: I've noted another post on this forum regarding a similar problem.

Thank you in advance !

I attach some screenshots.

1_Error_Details > it seems regards this particular line:
$colWidth=round(($displayWidth) / $nbCol); // 3 columns should be displayable
If I change $displayWidth (that is not evaluated) with a constant value (e.g. 1200) it works

2_Error_Creating_New_Project > when trying to create a brand new project

and the complete phpinfo page

I hope it helps.
Best regards,
Marius

OK, thank you. Actually, going from php 7.1 to php 7.0 solved the problem.
thank you for you support,

Best regards.