For whatever reason pdf files that are opened via Opera that have spaces you can fill or type in can never save, I go to the download button on the top right and click save with changes and nothing happens but all the saving without changes works just fine. Any ideas how to fix this?

For whatever reason pdf files that are opened via Opera that have spaces you can fill or type in can never save, I go to the download button on the top right and click save with changes and nothing happens but all the saving without changes works just fine. Any ideas how to fix this?