Problems after changing settings in OPC configuration

[patbe60]

This happens only on my local environment using MAMP 7.2:

When I make any changes in the OPC configuration I get this message on each site in the FE:

- Unexpected control character found

To remove this message I have to reinstall every time the database.

Additionally when I remove products from the cart I get a https URL instead of http. Since https server on a local environment is not necessary, I then always get an error message instead of a message like "successfully removed".
No problems with version 2.0.457.

J 5.4.0
VM 4.6.4
OPC 2.0.459