What version of SavedInstances are you using?
Latest 7.0.4

What Locale of the Wow Client are you running? (eg enUS for American English)
Europe

Are you using SavedInstances with a Data Broker display? If so, what is the name and version of the display addon?
No

What steps will reproduce the problem?
1. Getting saved in new Mythic: "Return to Karazhan"
2. -
3. -

What is the expected output? What do you see instead?
Text in chat (general) need to report bug "cannot find instance save in SavedInstances"
http://i.imgur.com/L6Bgbs5.jpg

Do you have lua errors enabled? (Interface/Help/Display Lua Errors) Do you have an error log of what happened?
YES (no lua error popup) - Only chat message

Are you disembedding your addons and addon libraries?
addons are not causing issues here or working against each other.
only using SavedInstances to track saves or kills of bosses.

Please provide any additional information below.
http://i.imgur.com/L6Bgbs5.jpg

Check picture and you see what i mean.