Explain to he.net that your current site can't run on php 7.2 (which is indeed the issue here). Ask them to drop it back (I think your current site can't use any version of php 7, so it will need to be 5). You may be able to do that yourself via CPanel.

Once you get access again, take another backup (database and files), for safe keeping. Then, consider upgrading the version of concrete5 you're using to one that's compatible with php 7.2. There'shttps://documentation.concrete5.org/developers/background/version-hi... but I don't know just how far compatibility extends.

Thanks for prompt reply. I'm doing a back up now.

For the time being I'm redirecting to an old 'Front Page' site until I figure out what to do. (Not ideal.)

If I install the latest version of C5, will anything from the old site be salvageable? Pages, Themes, etc.

Or are we starting all over from scratch? (What a nightmare!)

Pull request [5820](https://github.com/concrete5/concrete5/pull/5820... ) dated 8-Aug 2017 references the same error message that you are receiving and provides changes to concrete5. Howeve, I see from your error message it looks like you were using an older version of concrete5 that has not been upgraded.

Keeping up with the dependencies of any CMS is a sprint not for the faint of heart, requiring regular maintenance and upgrades and fraught with the risk that at any major version upgrade the whole house of cards will come tumbling down. Even knowing this, I have been burned many times, unable to keep up. It is a hidden cost and not to mention terrible marketing to explain that risk up front.

With the recommended backup copy in hand maybe you could try the upgrade path? (As I have arrived on this scene after version 5.7 I have not tried these but ...) try taking a look at http://andrewembler.com/2015/11/upgrade-concrete5-sites-57-using-ou... .

It is ironic that that your original (old fashioned ?) *low-tech* website had to come to the rescue of the more complicated fancier site!

Thanks for your excellent reply. Yes, I'm paying for years of neglect. Should have kept C5 software current.

He.net moved the site to an older server still running the PHP 5 so we are back to 'normal' but warned that on May 30, this server is scheduled to be upgraded to PHP 7. So I have a little breathing room... (Can't say enough good things about Hurricane Electric.)

I will check our your suggested links. Wish me luck.

Now if only there were more hours in a day...

You aren't that far out of date. A simple upgrade from 5.6.3.5 to 5.6.4.0, which is compatible with PHP 7.2, is available.

Make a backup of your files and database. Disable the cache, then run the upgrade.

Re-enable the cache and you should be good to go...

Yes, I'm on 5.6.3.5 but I'd like to upgrade to the most current version so that when my ISP upgrades to PHP 7 I won't have to worry about this stuff (for a while.)

Is there a roadmap that explains how to go from Version 5.6.3.5 to whatever the most current stable version of C5?

There is no direct upgrade path from legacy to v8. The link above that @northdecoder posted from Andrew's site explains the process required to export your legacy content to be imported to a new install.

Note that any legacy packages, themes or custom blocks will not work with v8.

What I posted above will get you past the May 30th PHP 7 deadline, and you'd want to be on 5.6.4.0 in either case.

Hope I'm not bugging you but I can't figure out how to upgrade to 5.6.4.

When I try to upgrade I get the message;

Currently Running 5.6.3.5
No updates available.

Thanks again to everyone on this thread. Thanks especially to ConcreteOwl's instructions (which seems to have disappeared) I successfully upgraded to 5.6.4. So I should be good fo a few more years... (I hope.)