Mailgun Error generating email from mimetype

I am using mailgun to send emails, and it was working fine for a while but now, everytime i try to generate and send an email using the mime type, i get the following error,

Id:
3f99a7b5-ed29-4f92-8185-2125dff547a1
Time of Log:
2019-07-05 11:03:12
Request Key:bacb3a34-eae1-4e45-8e88-8b2c64d96c20
eSpace:
Back_Office
Tenant:
Users
User:

Session Id:
No session
Server:
S5NW2-LT78ZI
Module:

Message:


Error generating the email!


Environment InformationeSpaceVer: 0 (Id=3591, PubId=0, CompiledWith=11.0.212.0)
RequestUrl: http://bzco5i040.outsystemscloud.com/Back_Office/_TimerHandler.asmx (Method: POST)
AppDomain: /LM/W3SVC/43/ROOT/Back_Office-19-132067963065337060
FilePath: C:\OutSystems\Sandboxes\BZCO5I040\Platform Server\running\Back_Office\
ClientIp: 127.0.0.1
Locale: en-US
DateFormat: yyyy-MM-dd
PID: 18488 ('w3wp', Started='7/4/2019 12:55:10 PM', Priv=553Mb, Virt=2115332Mb)
TID: 18
Thread Name:
.NET: 4.0.30319.42000
Stack:
Error generating the email!
   at ssMailgun.Actions.ActionSendMimeEmail(HeContext heContext, String inParamApiKey, String inParamDomain, String inParamFrom, String inParamTo, String inParamCc, String inParamBcc, Boolean inParamLogContent, String inParamEmailName, String inParameSpaceName, Int32& outParamSent_EmailId, String& outParamResult)

Has anybody encountered this issue and if so how do you fix it?


Are you using a rest call to send the email? or are you using the built in email functions and just using mailgun as the server?