I run several sites in c5, and some of them are updated to 5.5+
now here i have a lot of issues, some minor, some severe.

1. add ons do not install in 5.5 - I can install them through the dashboard directly from the marketplace in they are free. If not, I install them manually through ftp upload, but they do not show up at all in the dashboard.
Actually in the dashboard it looks like I have not installed any custom add ons at all, and I cannot uninstall them or update them. Some of them do show up on pages, and I can add them, others not.

2. When I add a content block only the left half of the editor is shown. I tried to resize it through the dashboard, but still I cannot find any way round this.

3. Some blocks that work perfectly well in 5.5 if they were added before updating will not install in 5.5
like the youtube gallery

any ideas?