I have the same problem!  I've removed my drivers and reinstalled.  It worked once when I first tried and has not worked since then...

Start the Dell Scan and FAX manager and check all the settings and IP are correct. Restart the PC and see if it connects. Otherwise go to Control Panel, Hardware, view devices and printers, select the printer, right click and select printer properties, click on ports tab, then configure port and UNCHECK the SNMP Status Enabled option if it is checked. Also, make sure you have updated the printer to the latest firmware.

I am having the same problem - NOT AVAILABLE

The first thing that you should do is try scanning using some other program. Paint, windows fax and scan and adobe acrobat(standard) should all work. If that works then we know the scan driver works and it is only the software that we are having a problem with. If the 1135 fax and scan is not working, try downloading the latest 2335 drivers and use the scan manager from that package. It should be a more recent version of the program and slightly more stable.

Hi, this is a Windows Firewall problem. I disabled the firewall and it works. Alternatively, you can add an exception to the firewall for this application:

C:\Windows\twain_32\Dell\DELL1135\Scan2PC.exe

Hope this helps

I have tried to disable firewall and have re-installed drivers...still get "not available" when I try to scan multiple pages. I can scan from flatbed one page at a time if I initiate scan from desktop.

This is very frustrating and it is good thing i don't keep a baseball bat next to scanner!! :)

I have the same problem scan to PC panel says NOT AVAILABLE

I have Windows 11 and noticed that after upgrading from Windows 10, the Dell Scan and Fax Manager for my Dell 1135n printer was giving an error "Error During Scan Please Restart The Program And/or Switch The Device Off..."  I had to make my own fix.  First I downloaded and installed an update for a Samsung printer, I know it sounds wonky, but it worked.  Go here http://org.downloadcenter.samsung.com/downloadfile/ContentsFile.aspx?DSite=UNI_SEC&CttFileID=7039669&CDCttType=SW&ModelType=N&ModelName=SL-C480&VPath=SW/201805/20180530152054554/win10_rs4_patch_adding_pcfax-fix.zip&OriginYN=N (you may have to copy and paste the link into your browser, I had to).  Then restart your computer. 

You might be ablet to skip this next part...[After installing the update and restarting, I played with the buttons on the printer and it would bring up the Scan 2 PC app.  After a few tries scanning differnt images/text, I then did the following....]

Next, navigate to the directory for the Scan and Fax Manager and delete the program itself.  Then reinstall the complete 1135n Printer software suite for Windows 10 (I am using 64 bit).  After that, the Scan and Fax manager should be working just fine with your printer. You'll have to reinput all your defaults, but it'll work!  

@Mebdrew​ Thank you very much. This worked great. Just clicked on the link, downloaded and installed, restarted the computer and scanned my documents. This was on Windows 11.