I have been using Slim PHP framework to provide my API service (https://api.rsywx.com).
Recently, I updated my PHP to 8.1 and when I visited the site, it gives the following error:
{
"statusCode": 500,
"error": {
"type": "SERVER_ERROR",
"description": "ERROR: Return type of App\\Application\\Actions\\ActionPayload::jsonSerialize() should either be compatible with JsonSerializable::jsonSerialize(): mixed, or the #[\\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice on line 67 in file \/home\/tr\/www\/api.rsywx.com\/src\/Application\/Actions\/ActionPayload.php."
}
}
I have not changed anything in my source code, so I guess the problem raises from Slim framework itself.
Any hints to solve this issue?