gnucash crash

[Arkajyoti Misra]

Hello everybody,
I am new to this list. 
I have been using Gnucash to keep track of personal finance for less
than a month. Everything was running smooth until midnight yesterday.
After the month changed to April each time I am trying to access my
accounts Gnucash is saying that it cannot obtain the lock file. If I
try to open my account anyway it is crashing. I got the following
error message:

Error: create_each_transaction_he...(): No account for guid
[00000000000000000000000000000000], cancelling SX [rent] creation.
Error: create_each_transaction_he...(): Some error in new transaction
creation...

** ERROR **: file dialog-sxsincelast.c: line 1614 (sxsincelast_init):
assertion failed: (nextPage)
aborting...
Aborted

Please help.

Arko.