The current Accept HTTP header used by Cloudflow is incorrect:

Accept: application/json, text/plain, */*

While RedHat/OpenStack do not seem to have advertised the change (from what I found/read), the default Content-Type for the /v2/executions Mistral REST API has switched from application/json to application/xml between v7 (Rocky) & v15 (Zed); no idea on exactly when.

While the seemingly undocumented change from Mistral would be problematic, the Accept header from Cloudflow remains the main struggle here, as Cloudflow does not actually support anything other than application/json.

The required fox would be to switch to:

Accept: application/json

Currently, I see 2 ways to solve the problem:

• angular/common fixing the way it handles Accept depending on the expected output format; cf. HTTP Accept header incorrect when requiring JSON response angular/angular#48505
• Setting the Accept HTTP header in the headers parameter of the HttpClient call; cf current master code section.