If “Canvas API” is disabled in a Salesforce environment, the following error message appears when you display the VyNDEX tab in Salesforce.
There was an error rendering Force.com Canvas application [VyNDEX].
Unable to retrieve signed request from the server. Please try your request later.
CANVAS_API_DISABLED: Force.com Canvas API is not enabled for this Organization or Partner.
The license holder of the Salesforce environment which generates this error must make a request to Salesforce.com to enable “Canvas API”.
The user can use VyNDEX services while this error is occurring.
(This error does not affect access Salesforce from VyNDEX Excel add-in.)
(Updated on August 31st, 2016)