SAP issue - Information about bug: "Unable to Cast ..."

Update: B1UP 5.0.1 and higher now uses new techniques found to suppress and greatly reduce this issue. It is not a 100% and we continue to work with SAP but it is highly recommended to move to at least this B1UP version (http://www.boyum-it.com/sbo)

This post explain the known information about the following bug:

- In releases prior to B1UP 4.3 it look like screenshot 1
- In release B1UP 4.3 and higher the error is presented like in screenshot 2 (Nicer and more information)

FAQ about the bug

Q: Where in SAP/B1UP does the error present itself?
A: The error seem to be completely random in nature right now. It can happen in the start of the day or the end of the day... It can happen one day and not the next if it gone. It can happen opening windows, pressing buttons. In summary; truly random

Q: Why does the bug happen?
A: The exact reason is not yet known. It is related to an old instability bug in the SAP SDK that can happen in long operations (several minutes) and we have seen the issue in rare cases for several years (SBO2007 releases and forward). The issue is explained by SAP in the Note: 1506163 (https://websmp130.sap-ag.de/sap/support/notes/1506163), but in the last half a year the error seem to come more often and also during operations that are very short.

Q: Do you have any theories on why it happens?
A: Yes, we have a bunch of theories but without being able to look into the SAP Source code they are only theories so the following is only based on our observations. We can see that it can happen all kind of OS'es (WinXp, Win7, Win2008) and also several SAP version (2007, 8.8, 8.81, 8.82) and B1UP versions (3.8 --> 4.3) so the issue does not seem to be version specific. It seem that the error happen more often on slower machines so there we think it is a resource issue. Our current theory is that Windows contains something called a message pump and the the SAP client in some scenarios spam this pump that "overflow" and cause the error to happen. Another theory is that it is some kind of network issue.

Q: Why is this bug not fixed ages ago?
A: The SAP Note is many years old but is is not known by Boyum IT A/S why it is not fixed yet. For certain long operations there is a workaround to the issue (Using .Net Threads) but the new development in this happening on on shorter operation have caused it to become a much more serious problem and for that reason we are pressuring SAP to get a solution as soon as possible.

Q: What have Boyum IT done to get rid of the error so far?
A: The error and observations are logged to SAP Support with high priority but they do not yet know the reason and have no final solution except for the current workarounds mentioned in the Note.

Q: Is the bug dangerous?
A: From a technical standpoint the error is not dangerous at all (but very annoying). But the error prevent B1UP to do it's work and if the event happen during something that was important during the business logic that business logic was not executed (Example: if you had mandatory fields that should have been checked that check might not happen) [This is the main reason that we are not just suppressing the error as people need to be aware that their normal flow perhaps did not happen]

Q: I have the bug here and now. What can I do?
A: As mention there is no final solution but here is some things to try:

(1) Try to reset the %temp% folder SM_OBS_DLL [Hornestly we can see how this should be able to help but observation says differently]

(2) Try to resintall the SAP Business One client [This have been quite effective so far solving the issue 90% of the times]

(3) Try SAP's RegEdit workaround in the above SAP note.

Q: You know about the issue. Should I still log it to you?
A: Yes, please do so as we are still working on a pattern on why it happens so if you log it please mention SAP version, B1UP version, Windows Version, when the error happen and if you have tried above workarounds.

Q: What's next?
A: SAP have promised us a new kind of workaround in February 2012 (SBO8.81 PL11). When this comes we will look more into that part but in the mean time we are doing two things:

(1) Tracking all instances of the issue to find a common pattern to help come closer to the issue

(2) Try various techniques to minimize the annoyance of the issue (If we can't get rid of the problem the least we can try is make as small of an impact as possible). [B1UP 5 as an example supress the error in certain areas so it is not as annoying]

This thread will be updated if/when we found more information as time progress but we are deeply sorry for the problems this issue is causing right now but we wanted to let you know that we are doing our best to get rid of it in cooperation with SAP.