Re: https://blog.whmcs.com/?t=69402

WHOOPS! Sorry everyone. It looks like we caused a few problems with the patches we released earlier today. We are truly sorry for any inconvenience this has caused.

As a result we have re-issued the patches to address all issues reported to us so far, so please head back to the downloads section and re-download and then upload/apply the files to your installation. Again as before, no install or upgrade process is required so long as you aren't changing version number (you can find your current version number in Help > Check for Updates).
[INDENT]
4.0 series: https://www.whmcs.com/download/170/12mar2013patchv40
4.1 series: https://www.whmcs.com/download/174/12mar2013patchv41
4.2 series: https://www.whmcs.com/download/178/12mar2013patchv42
4.3 series: https://www.whmcs.com/download/182/12mar2013patchv43
4.4 series: https://www.whmcs.com/download/186/12mar2013patchv44
4.5 series: https://www.whmcs.com/download/190/12mar2013patchv45
v5.0.4: https://www.whmcs.com/download/194/12mar2013patchv504
v5.1.4: https://www.whmcs.com/download/198/12mar2013patchv514
[/INDENT]

The changes contained within are to fix unforeseen compatability issues and are not security related.

If you do experience any further problems or issues, please use our new dedicated bug report submission tool to report them to us which is now available @ https://bugs.whmcs.com/