strategy_version_not_code
What happened
Opening a version in the Studio reads its code and rebuilds it as blocks. That works from a version written as code whose check has passed. A version that is already a Studio version, or whose check failed or has not finished, is refused with 409.
What to do
Wait for the check to finish, or fix what it reports and save again.
Example
json
{
"error": "Only a checked code version can open in the Studio.",
"code": "strategy_version_not_code"
}