I have the same kind of issue sometime with some tasks but not with Salesforce, with SAP Connector :
Error: Invalid custom connector QvSAPConnector.dll
Used QVConnect: C:\Program Files\QlikView\Distribution Service\QvConnect64.EXE
General Script Error
The task finished with success when I launch it again.
My connection string is basic :
CUSTOM CONNECT TO "Provider=QvSAPConnector.dll;ASHOST=<MYHOST>;TimeOutFetch=3600;SYSNR=01;CLIENT=100;KeepCasing=1;NullDate=1;XUserId=QSTFFBdKfKUYUENJZE;XPassword=HcTWWUZNJDdATYYK;";
SAP Transport information: version: E6DK900375; date: 20131029; time: 100211; SAP basis: 701;
SAP Connector version : 5.7 SR1
Do you have find the reason ? (May be the 24 of January is a bad day )
A problem with QvConnect64.EXE ?
Thanks & Regards,