I did an update to my survey site and after logging out and logging back in as it directed me to, it said it was missing a logo file. I took one of the logos from the other folders and moved it there, as the logo did look the same. Anyways, logging back in produced the following look:
The approach Ben linked to (thanks!) highly depend on the version you updated from. Which version did you use prior to the update?
Please also check if a backup of DB and files was created at /limesurvey/tmp.
Best regards/Beste Grüße,
Dr. Marcel Minke
survey-consulting.com
offlinesurveys.com
Feel free to contact me by email for professional LimeSurvey support!