Object of class VmImage could not be converted to string

[EvanGR]

Hello,

In one of my products (frontend) I am getting an error page with the following message:

Code Select Expand

0 - Object of class VmImage could not be converted to string

It only happens with a single product so far (in a site with thousands of products). Therefore it's an edge case.
The product loads fine in the backend, including the product image, and I tried re-saving it but this didn't fix it.

Any suggestions on how to approach/debug this?

Thanks

[VM 3.8.9 10473]

[Milbo]

enable the joomla debug and check the trace and post it here, so I can take a look. At best not only the last line, just the last 3-4 lines

[EvanGR]

I enabled Joomla debug, and error level reporting to maximum.
Nothing changed in the error page. (no debug information)

Discovered something super-weird... if I change the product title, e.g. add a blank space at the beginning, the product works fine!
If I change it back to the original, it crashes again.
Here's the original product title: Φορτιστής, συντηρητής και αποθειωτής συσσωρευτών 2 θέσεων φόρτισης NOCO GENIUS2X2 4Α (2Α/θέση φόρτ)

[pinochico]

for debug we use n3t debug plugin:
https://bitbucket.org/n3t/n3t-debug/downloads/