More informative error on petab version mismatch

Closes #152.

Author: dweindl

src/petab_gui/controllers/mother_controller.py

@@ -54,6 +54,7 @@
     filtered_error,
     prompt_overwrite_or_append,
 )
+from petab.versions import get_major_version
 
 
 class MainController:
@@ -730,6 +731,12 @@ def open_yaml_and_load_files(self, yaml_path=None, mode="overwrite"):
             with open(yaml_path) as file:
                 yaml_content = yaml.safe_load(file)
 
+            if (major := get_major_version(yaml_content)) != 1:
+                raise ValueError(
+                    f"Only PEtab v1 problems are currently supported. "
+                    f"Detected version: {major}.x."
+                )
+
             # Resolve the directory of the YAML file to handle relative paths
             yaml_dir = Path(yaml_path).parent