When I click on Launch Accounts 2017 R2 using Firefox (version 56.0), I get the following error:
An error occurred during a connection to hosted.reckon.com.au. Invalid OCSP signing certificate in OCSP response. Error code: SEC_ERROR_OCSP_INVALID_SIGNING_CERT
There is no continue option. If I try Edge, the same problem does not occur.
Searching for SEC_ERROR_OCSP_INVALID_SIGNING_CERT and Firefox finds a number of hits with other sites having the same problem. One post lists a way of turning this behavior off in Firefox, if you are keen. https://answers.microsoft.com/en-us/windows/forum/windows_other-ecoms/secerrorocspinvalidsigningcert...
Clicking on Show site information for the page, choosing the >, then clicking More information, and then the Security tab displays the technical details of the error as shown in the attached screen shot.

As I am not willing to turn off the checking in Firefox, looks like I will use Edge until Reckon fix this!
An error occurred during a connection to hosted.reckon.com.au. Invalid OCSP signing certificate in OCSP response. Error code: SEC_ERROR_OCSP_INVALID_SIGNING_CERT
There is no continue option. If I try Edge, the same problem does not occur.
Searching for SEC_ERROR_OCSP_INVALID_SIGNING_CERT and Firefox finds a number of hits with other sites having the same problem. One post lists a way of turning this behavior off in Firefox, if you are keen. https://answers.microsoft.com/en-us/windows/forum/windows_other-ecoms/secerrorocspinvalidsigningcert...
Clicking on Show site information for the page, choosing the >, then clicking More information, and then the Security tab displays the technical details of the error as shown in the attached screen shot.
As I am not willing to turn off the checking in Firefox, looks like I will use Edge until Reckon fix this!