We are in the middle of doing a Bank Deposit and we are using no 3rd party software, the user has Poweruser permission, and the same error happens for multiple workstations and as well for the SA user.
Bottom line is that we enter the Bank ID and are immediately told that a transaction for the Bank has been started and that we need to run Checklinks in order to continue the process. Well - ok - we will do this once right now - complete the process - enter one or more transactions and complete the deposit for (say) 11/13/2015 and now we want to continue onto the deposit for 11/14/2015.
We enter the new date, select the same bank ID and get the error that there is already a transaction started for the bank ID in question - we need to run Checklinks in order to continue.
Yes - we have already posted the first transactions,
No - there is no one else doing bank deposits at this time.
In addition to this, if we try to click on OK we get a message that tells us that a TMP file for Cash Management can not be found due to a missing path.

Challenging part is we thought we had this fixed two weeks ago - no further errors occured after extensive rebuilding and maintenance in the system - and then POW - this morning while we are working on something completely unrelated the user suggests while he is waiting on my SQL querey for something unrelated that he could complete a Bank deposit - the error message appears. He has done 10 or 12 deposits to the same bank in the past couple of weeks and did not encounter a single error.