Upload OpenDTU to ESP32 dev board fails

about 6 months ago I successfully used PlatformIO IDE to flash “Open DTU” to ESP 32 development boards. My system was and is Windows 11.
Recently I retried using the formerly successful OpenDTU files, but instead of flashing I get error messages “command ‘platformio-ide.build’ not found” and “command ‘platformio-ide.upload’ not found” as well as “; PlatformIO Project Configuration File” (the “;” is underlined in red).
Meanwhile I updated VS code, platformIO IDE as well as the latest github.com files - however the error messages remain the same.
I would be grateful to receive “simple” support, as I am not at all a PC expert…