Looking for help diagnosing problems.

[Hammerhydra]

Using a Mars Pro with water-washable resin. Had it since September.
Changed the FEP film the other day (not the first time I've changed it, used films from the same pack without issue) and had a lot of problems since.
Currently, prints are coming out with some striping & roughness as it looks like layers are not alligned perfectly, and some extra resin forming thin, flexible  membranes around parts of the print. It's not consistent across the whole print though - some parts come out perfectly, others are a bit of a mess.
So far tried:

• Replacing the FEP again, tightening it to just under 400hz.
  
• Cleaning the screen & FEP.
  
• Lubricating the FEP with a little silicone spray.
  
• Re-levelling & re-zeroing the build plate.
  
• Cleaning & sanding the build plate.
  
• Using various print files (all of which were working well before all this started).
  
• Using a fresh bottle of resin.
  

Can anyone suggest possible causes/solutions?

[cliffyk]

Any recent changes in ambient conditions (temp/humidity mostly)?

[Hammerhydra]

Any recent changes in ambient conditions (temp/humidity mostly)?

Nothing I can think of (printer is in a room with central heating, kept at a warm & consistent temperature while printing).
Ran the LCD & Tank cleaning tests - no flaws in the LCD I can see. Also found out the names for the issues - seeing both ragging and rashing (although ragging membranes are bot horizontal and vertical - don't know what that means). Will get some photos later.

[Hammerhydra]

Any recent changes in ambient conditions (temp/humidity mostly)?

Nothing I can think of (printer is in a room with central heating, kept at a warm & consistent temperature while printing).
Ran the LCD & Tank cleaning tests - no flaws in the LCD I can see. Also found out the names for the issues - seeing both ragging and rashing (although ragging membranes are bot horizontal and vertical - don't know what that means). Will get some photos later.

Wondering if it could be the FEP film. Using these, and some of the reviews suggest similar issues (first one from the pack worked fine, but maybe I was just lucky). Does that sound feasible?
https://www.amazon.co.uk/Thickness-Compa...510&sr=8-6

[cliffyk]

How old is the resin, has it been stored uncapped?

I cannot help much with eater washable resin, tried it once with very poor results and vowed "never again". In the first it was not really water washable, it was also VERY brittle, and had a tendency to rag and rash. Elegoo was cool, they sent me a kilo of plain ol' gray as compensation for my troubles...

[Hammerhydra]

How old is the resin, has it been stored uncapped?

I cannot help much with eater washable resin, tried it once with very poor results and vowed "never again". In the first it was not really water washable, it was also VERY brittle, and had a tendency to rag and rash. Elegoo was cool, they sent me a kilo of plain ol' gray as compensation for my troubles...

Brand new bottle, always stored sealed.
Have printed this file dozens of times with the same type of water washable resin with good results, until these current issues started.