Thanks for sharing Timothy. We have been investigating this further the past 24 hours and came to the same conclusion. It seems there are two possible causes for the issues in this thread.
The warnings are indeed generated because text was input into the Event Cost field instead of a number. Up until a few versions back The Events Calendar allowed you to input text (like “No Cost”) into the cost field. But inputting text has always caused errors in various scenarios (and those errors have become more numerous in 4.0). So a few versions ago we made it so The Events Calendar would no longer allow text in the Event Cost field.
However, events that were created in ancient versions of the calendar may still contain text, and will cause the PHP Warning seen in this thread. Further, importing an event via CSV will still allow text to be input, also causing error (this is a bug we are working on).
To fix this you will need to find all events which have text in that field and change them to a number. To do this enmasse you can run some MySQL commands, perhaps from PHPMyAdmin. To get a list of all events which have this issue you could run the following SQL in your WordPress database:
SELECT * FROM wp_postmeta
WHERE
meta_key=’_EventCost’ AND
meta_value!=” AND
concat(”, meta_value * 1) != meta_value
You could then edit them on a case-by-case basis. If you wish to convert many of these at once you can run some SQL update commands. For instance the following will change everywhere that the word “No Cost” was typed in to the Event Cost field to the number 0, since 0 is treated as free in The Events Calendar.
UPDATE wp_postmeta SET meta_value=’0′
WHERE meta_key=”_EventCost” AND meta_value=”No Cost”
If you wish to instead remove the cost value from all of the problem events, run this:
UPDATE wp_postmeta SET meta_value=”
WHERE
meta_key=’_EventCost’ AND
meta_value!=” AND
concat(”, meta_value * 1) != meta_value
Please note, there is always risk with running SQL commands on your database. It is a VERY good idea to make a database backup before dabbling with your data.
I am very sorry for the inconvenience. At least now we have established what is causing it and have a fix though. Please let me know if you have any questions.
Cheers!
– Brook
