Bitmap annotation not added in PDF.

or you check that is there 2 documents set same cache at one time.
this is invalid.

In Reader Activity open doc and set cache.
now when redirect to Preview activity, here open updated pdf(using new doc and here set cache not used).
On back button using doc.Close(); ,resume Reader activity.

Does it effecting annotation?

Please send us complete code for adding bitmap.
We were using 2.8.9 version before this.
updated with 3.1. Tell us required file changes for that.

first of all, 2.8.9 may some issue for AddAnnotBitmap() and fixed in later version.
second point: to ensure Document.SetCache() invoked only once and succeeded.

Yes, We are sure that setCache() invoked only once.
We are not getting what is the problem now.