Fatal error version 2

I have the same error in MailPoet 2 after upgrading to WordPress 5.2.
It’s happening on one site I maintain but not on another site.
I suspected incompatibility with another plugin, but deactivating all other plugins doesn’t cure the problem.

I am working on upgrading to MailPoet 3 but I will need to leave MailPoet 2 activated so that the MailPoet 2 newsletter archive is accessible. Or is there another way to view the MailPoet 2 archive?

This is the message I see

The site is experiencing technical difficulties. Please check your site admin email inbox for instructions.

PHP ERROR:array(4) {
  ["type"]=>
  int(4)
  ["message"]=>
  string(36) "syntax error, unexpected end of file"
  ["file"]=>
  string(115) "/home/xxxxxx/public_html/web/wp-content/plugins/wysija-newsletters/helpers/render_engine.php(600) : eval()'d code"
  ["line"]=>
  int(1)
}

I’m getting the same error.

Rolling back to PHP 7.2 (from 7.3) prevents the error from occurring.

I’ve just finished migrating one of three websites that use MailPoet to version 3. For the other two that are still using version 2, I’ve had to roll back PHP to keep the sites functioning.

A fix for this issue would be appreciated…

Thanks @widecast for the temporary workaround.
I was on PHP 7.3.5.
After backing down to 7.1 or 7.2 the problem goes away (or is hidden).

I still think that fixing MailPoet 2 is the wrong approach.
There should be a way to display the MailPoet 2 newsletter archive without requiring MailPoet 2 to be installed.
Maybe some way to export the SQL table containing the MailPoet 2 newsletters and import as normal posts which don’t require any special wysija CSS classes.

The problem seems to lie in another line in /wp-content/plugins/wysija-newsletters/helpers/render_engine.php. The eval error mentioned by @adriandw is only an effect of a failing regexp parse. This warning is the real cause:

PHP Warning: preg_match_all(): Compilation failed: invalid range in character class at offset 11 in XXX/web/wp-content/plugins/wysija-newsletters/helpers/render_engine.php on line 593

The problem in that line is caused by this constant at line 43 of that file:

const _VAR = '([\$#])([\w-_\.]+)';

In PHP 7.3, for some reason the dash in the second character class is interpreted as a range mark instead of a literal dash. Probably because now, you can make ranges between classes like \w.

So the fix is easy (and NOT worth the 19 dollars per site that some companies ask for it): change this line to

const _VAR = '([\$#])([\w\-_\.]+)';

And all is fine again.

Hope to help you all out this way.

Regrds, Jelmer

• This reply was modified 6 years, 6 months ago by jelmerjellema. Reason: I hate code blocks with backticks. That's why
• This reply was modified 6 years, 6 months ago by jelmerjellema.

Strange… We run php 7.3.7 and did have this problem. Maybe some strange setting somewhere?

Good to hear the fix worked out for you!

Mailpoet 3 is for a lot of people not a good fix on the short term. So the *fix* is my fix above, while the *solution* for the long term will be either buying MailPoet 3 or finding some other solution.